net/mac80211/wpa.c

   1 /*
   2  * Copyright 2002-2004, Instant802 Networks, Inc.
   3  * Copyright 2008, Jouni Malinen <j@w1.fi>
   4  * Copyright (C) 2016 Intel Deutschland GmbH
   5  *
   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  */
  10
  11 #include <linux/netdevice.h>
  12 #include <linux/types.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/compiler.h>
  15 #include <linux/ieee80211.h>
  16 #include <linux/gfp.h>
  17 #include <asm/unaligned.h>
  18 #include <net/mac80211.h>
  19 #include <crypto/aes.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "michael.h"
  23 #include "tkip.h"
  24 #include "aes_ccm.h"
  25 #include "aes_cmac.h"
  26 #include "aes_gmac.h"
  27 #include "aes_gcm.h"
  28 #include "wpa.h"
  29
  30 ieee80211_tx_result
  31 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
  32 {
  33         u8 *data, *key, *mic;
  34         size_t data_len;
  35         unsigned int hdrlen;
  36         struct ieee80211_hdr *hdr;
  37         struct sk_buff *skb = tx->skb;
  38         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  39         int tail;
  40
  41         hdr = (struct ieee80211_hdr *)skb->data;
  42         if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
  43             skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
  44                 return TX_CONTINUE;
  45
  46         hdrlen = ieee80211_hdrlen(hdr->frame_control);
  47         if (skb->len < hdrlen)
  48                 return TX_DROP;
  49
  50         data = skb->data + hdrlen;
  51         data_len = skb->len - hdrlen;
  52
  53         if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
  54                 /* Need to use software crypto for the test */
  55                 info->control.hw_key = NULL;
  56         }
  57
  58         if (info->control.hw_key &&
  59             (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
  60              tx->local->ops->set_frag_threshold) &&
  61             !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
  62                 /* hwaccel - with no need for SW-generated MMIC */
  63                 return TX_CONTINUE;
  64         }
  65
  66         tail = MICHAEL_MIC_LEN;
  67         if (!info->control.hw_key)
  68                 tail += IEEE80211_TKIP_ICV_LEN;
  69
  70         if (WARN(skb_tailroom(skb) < tail ||
  71                  skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
  72                  "mmic: not enough head/tail (%d/%d,%d/%d)\n",
  73                  skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
  74                  skb_tailroom(skb), tail))
  75                 return TX_DROP;
  76
  77         key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
  78         mic = skb_put(skb, MICHAEL_MIC_LEN);
  79         michael_mic(key, hdr, data, data_len, mic);
  80         if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
  81                 mic[0]++;
  82
  83         return TX_CONTINUE;
  84 }
  85
  86
  87 ieee80211_rx_result
  88 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
  89 {
  90         u8 *data, *key = NULL;
  91         size_t data_len;
  92         unsigned int hdrlen;
  93         u8 mic[MICHAEL_MIC_LEN];
  94         struct sk_buff *skb = rx->skb;
  95         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  96         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  97
  98         /*
  99          * it makes no sense to check for MIC errors on anything other
 100          * than data frames.
 101          */
 102         if (!ieee80211_is_data_present(hdr->frame_control))
 103                 return RX_CONTINUE;
 104
 105         /*
 106          * No way to verify the MIC if the hardware stripped it or
 107          * the IV with the key index. In this case we have solely rely
 108          * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
 109          * MIC failure report.
 110          */
 111         if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
 112                 if (status->flag & RX_FLAG_MMIC_ERROR)
 113                         goto mic_fail_no_key;
 114
 115                 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
 116                     rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
 117                         goto update_iv;
 118
 119                 return RX_CONTINUE;
 120         }
 121
 122         /*
 123          * Some hardware seems to generate Michael MIC failure reports; even
 124          * though, the frame was not encrypted with TKIP and therefore has no
 125          * MIC. Ignore the flag them to avoid triggering countermeasures.
 126          */
 127         if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
 128             !(status->flag & RX_FLAG_DECRYPTED))
 129                 return RX_CONTINUE;
 130
 131         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
 132                 /*
 133                  * APs with pairwise keys should never receive Michael MIC
 134                  * errors for non-zero keyidx because these are reserved for
 135                  * group keys and only the AP is sending real multicast
 136                  * frames in the BSS.
 137                  */
 138                 return RX_DROP_UNUSABLE;
 139         }
 140
 141         if (status->flag & RX_FLAG_MMIC_ERROR)
 142                 goto mic_fail;
 143
 144         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 145         if (skb->len < hdrlen + MICHAEL_MIC_LEN)
 146                 return RX_DROP_UNUSABLE;
 147
 148         if (skb_linearize(rx->skb))
 149                 return RX_DROP_UNUSABLE;
 150         hdr = (void *)skb->data;
 151
 152         data = skb->data + hdrlen;
 153         data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
 154         key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
 155         michael_mic(key, hdr, data, data_len, mic);
 156         if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
 157                 goto mic_fail;
 158
 159         /* remove Michael MIC from payload */
 160         skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
 161
 162 update_iv:
 163         /* update IV in key information to be able to detect replays */
 164         rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
 165         rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
 166
 167         return RX_CONTINUE;
 168
 169 mic_fail:
 170         rx->key->u.tkip.mic_failures++;
 171
 172 mic_fail_no_key:
 173         /*
 174          * In some cases the key can be unset - e.g. a multicast packet, in
 175          * a driver that supports HW encryption. Send up the key idx only if
 176          * the key is set.
 177          */
 178         cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
 179                                      is_multicast_ether_addr(hdr->addr1) ?
 180                                      NL80211_KEYTYPE_GROUP :
 181                                      NL80211_KEYTYPE_PAIRWISE,
 182                                      rx->key ? rx->key->conf.keyidx : -1,
 183                                      NULL, GFP_ATOMIC);
 184         return RX_DROP_UNUSABLE;
 185 }
 186
 187 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 188 {
 189         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 190         struct ieee80211_key *key = tx->key;
 191         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 192         unsigned int hdrlen;
 193         int len, tail;
 194         u64 pn;
 195         u8 *pos;
 196
 197         if (info->control.hw_key &&
 198             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 199             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
 200                 /* hwaccel - with no need for software-generated IV */
 201                 return 0;
 202         }
 203
 204         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 205         len = skb->len - hdrlen;
 206
 207         if (info->control.hw_key)
 208                 tail = 0;
 209         else
 210                 tail = IEEE80211_TKIP_ICV_LEN;
 211
 212         if (WARN_ON(skb_tailroom(skb) < tail ||
 213                     skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
 214                 return -1;
 215
 216         pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
 217         memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
 218         pos += hdrlen;
 219
 220         /* the HW only needs room for the IV, but not the actual IV */
 221         if (info->control.hw_key &&
 222             (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 223                 return 0;
 224
 225         /* Increase IV for the frame */
 226         pn = atomic64_inc_return(&key->conf.tx_pn);
 227         pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
 228
 229         /* hwaccel - with software IV */
 230         if (info->control.hw_key)
 231                 return 0;
 232
 233         /* Add room for ICV */
 234         skb_put(skb, IEEE80211_TKIP_ICV_LEN);
 235
 236         return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
 237                                            key, skb, pos, len);
 238 }
 239
 240
 241 ieee80211_tx_result
 242 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
 243 {
 244         struct sk_buff *skb;
 245
 246         ieee80211_tx_set_protected(tx);
 247
 248         skb_queue_walk(&tx->skbs, skb) {
 249                 if (tkip_encrypt_skb(tx, skb) < 0)
 250                         return TX_DROP;
 251         }
 252
 253         return TX_CONTINUE;
 254 }
 255
 256
 257 ieee80211_rx_result
 258 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 259 {
 260         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 261         int hdrlen, res, hwaccel = 0;
 262         struct ieee80211_key *key = rx->key;
 263         struct sk_buff *skb = rx->skb;
 264         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 265
 266         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 267
 268         if (!ieee80211_is_data(hdr->frame_control))
 269                 return RX_CONTINUE;
 270
 271         if (!rx->sta || skb->len - hdrlen < 12)
 272                 return RX_DROP_UNUSABLE;
 273
 274         /* it may be possible to optimize this a bit more */
 275         if (skb_linearize(rx->skb))
 276                 return RX_DROP_UNUSABLE;
 277         hdr = (void *)skb->data;
 278
 279         /*
 280          * Let TKIP code verify IV, but skip decryption.
 281          * In the case where hardware checks the IV as well,
 282          * we don't even get here, see ieee80211_rx_h_decrypt()
 283          */
 284         if (status->flag & RX_FLAG_DECRYPTED)
 285                 hwaccel = 1;
 286
 287         res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
 288                                           key, skb->data + hdrlen,
 289                                           skb->len - hdrlen, rx->sta->sta.addr,
 290                                           hdr->addr1, hwaccel, rx->security_idx,
 291                                           &rx->tkip_iv32,
 292                                           &rx->tkip_iv16);
 293         if (res != TKIP_DECRYPT_OK)
 294                 return RX_DROP_UNUSABLE;
 295
 296         /* Trim ICV */
 297         skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
 298
 299         /* Remove IV */
 300         memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
 301         skb_pull(skb, IEEE80211_TKIP_IV_LEN);
 302
 303         return RX_CONTINUE;
 304 }
 305
 306
 307 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
 308 {
 309         __le16 mask_fc;
 310         int a4_included, mgmt;
 311         u8 qos_tid;
 312         u16 len_a;
 313         unsigned int hdrlen;
 314         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 315
 316         /*
 317          * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
 318          * Retry, PwrMgt, MoreData; set Protected
 319          */
 320         mgmt = ieee80211_is_mgmt(hdr->frame_control);
 321         mask_fc = hdr->frame_control;
 322         mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
 323                                 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
 324         if (!mgmt)
 325                 mask_fc &= ~cpu_to_le16(0x0070);
 326         mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 327
 328         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 329         len_a = hdrlen - 2;
 330         a4_included = ieee80211_has_a4(hdr->frame_control);
 331
 332         if (ieee80211_is_data_qos(hdr->frame_control))
 333                 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 334         else
 335                 qos_tid = 0;
 336
 337         /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
 338          * mode authentication are not allowed to collide, yet both are derived
 339          * from this vector b_0. We only set L := 1 here to indicate that the
 340          * data size can be represented in (L+1) bytes. The CCM layer will take
 341          * care of storing the data length in the top (L+1) bytes and setting
 342          * and clearing the other bits as is required to derive the two IVs.
 343          */
 344         b_0[0] = 0x1;
 345
 346         /* Nonce: Nonce Flags | A2 | PN
 347          * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
 348          */
 349         b_0[1] = qos_tid | (mgmt << 4);
 350         memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
 351         memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
 352
 353         /* AAD (extra authenticate-only data) / masked 802.11 header
 354          * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 355         put_unaligned_be16(len_a, &aad[0]);
 356         put_unaligned(mask_fc, (__le16 *)&aad[2]);
 357         memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 358
 359         /* Mask Seq#, leave Frag# */
 360         aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
 361         aad[23] = 0;
 362
 363         if (a4_included) {
 364                 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
 365                 aad[30] = qos_tid;
 366                 aad[31] = 0;
 367         } else {
 368                 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
 369                 aad[24] = qos_tid;
 370         }
 371 }
 372
 373
 374 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
 375 {
 376         hdr[0] = pn[5];
 377         hdr[1] = pn[4];
 378         hdr[2] = 0;
 379         hdr[3] = 0x20 | (key_id << 6);
 380         hdr[4] = pn[3];
 381         hdr[5] = pn[2];
 382         hdr[6] = pn[1];
 383         hdr[7] = pn[0];
 384 }
 385
 386
 387 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
 388 {
 389         pn[0] = hdr[7];
 390         pn[1] = hdr[6];
 391         pn[2] = hdr[5];
 392         pn[3] = hdr[4];
 393         pn[4] = hdr[1];
 394         pn[5] = hdr[0];
 395 }
 396
 397
 398 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
 399                             unsigned int mic_len)
 400 {
 401         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 402         struct ieee80211_key *key = tx->key;
 403         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 404         int hdrlen, len, tail;
 405         u8 *pos;
 406         u8 pn[6];
 407         u64 pn64;
 408         u8 aad[2 * AES_BLOCK_SIZE];
 409         u8 b_0[AES_BLOCK_SIZE];
 410
 411         if (info->control.hw_key &&
 412             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 413             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 414             !((info->control.hw_key->flags &
 415                IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
 416               ieee80211_is_mgmt(hdr->frame_control))) {
 417                 /*
 418                  * hwaccel has no need for preallocated room for CCMP
 419                  * header or MIC fields
 420                  */
 421                 return 0;
 422         }
 423
 424         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 425         len = skb->len - hdrlen;
 426
 427         if (info->control.hw_key)
 428                 tail = 0;
 429         else
 430                 tail = mic_len;
 431
 432         if (WARN_ON(skb_tailroom(skb) < tail ||
 433                     skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
 434                 return -1;
 435
 436         pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
 437         memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
 438
 439         /* the HW only needs room for the IV, but not the actual IV */
 440         if (info->control.hw_key &&
 441             (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 442                 return 0;
 443
 444         hdr = (struct ieee80211_hdr *) pos;
 445         pos += hdrlen;
 446
 447         pn64 = atomic64_inc_return(&key->conf.tx_pn);
 448
 449         pn[5] = pn64;
 450         pn[4] = pn64 >> 8;
 451         pn[3] = pn64 >> 16;
 452         pn[2] = pn64 >> 24;
 453         pn[1] = pn64 >> 32;
 454         pn[0] = pn64 >> 40;
 455
 456         ccmp_pn2hdr(pos, pn, key->conf.keyidx);
 457
 458         /* hwaccel - with software CCMP header */
 459         if (info->control.hw_key)
 460                 return 0;
 461
 462         pos += IEEE80211_CCMP_HDR_LEN;
 463         ccmp_special_blocks(skb, pn, b_0, aad);
 464         ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
 465                                   skb_put(skb, mic_len), mic_len);
 466
 467         return 0;
 468 }
 469
 470
 471 ieee80211_tx_result
 472 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
 473                               unsigned int mic_len)
 474 {
 475         struct sk_buff *skb;
 476
 477         ieee80211_tx_set_protected(tx);
 478
 479         skb_queue_walk(&tx->skbs, skb) {
 480                 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
 481                         return TX_DROP;
 482         }
 483
 484         return TX_CONTINUE;
 485 }
 486
 487
 488 ieee80211_rx_result
 489 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
 490                               unsigned int mic_len)
 491 {
 492         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 493         int hdrlen;
 494         struct ieee80211_key *key = rx->key;
 495         struct sk_buff *skb = rx->skb;
 496         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 497         u8 pn[IEEE80211_CCMP_PN_LEN];
 498         int data_len;
 499         int queue;
 500
 501         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 502
 503         if (!ieee80211_is_data(hdr->frame_control) &&
 504             !ieee80211_is_robust_mgmt_frame(skb))
 505                 return RX_CONTINUE;
 506
 507         if (status->flag & RX_FLAG_DECRYPTED) {
 508                 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
 509                         return RX_DROP_UNUSABLE;
 510                 if (status->flag & RX_FLAG_MIC_STRIPPED)
 511                         mic_len = 0;
 512         } else {
 513                 if (skb_linearize(rx->skb))
 514                         return RX_DROP_UNUSABLE;
 515         }
 516
 517         data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
 518         if (!rx->sta || data_len < 0)
 519                 return RX_DROP_UNUSABLE;
 520
 521         if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
 522                 int res;
 523
 524                 ccmp_hdr2pn(pn, skb->data + hdrlen);
 525
 526                 queue = rx->security_idx;
 527
 528                 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
 529                              IEEE80211_CCMP_PN_LEN);
 530                 if (res < 0 ||
 531                     (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
 532                         key->u.ccmp.replays++;
 533                         return RX_DROP_UNUSABLE;
 534                 }
 535
 536                 if (!(status->flag & RX_FLAG_DECRYPTED)) {
 537                         u8 aad[2 * AES_BLOCK_SIZE];
 538                         u8 b_0[AES_BLOCK_SIZE];
 539                         /* hardware didn't decrypt/verify MIC */
 540                         ccmp_special_blocks(skb, pn, b_0, aad);
 541
 542                         if (ieee80211_aes_ccm_decrypt(
 543                                     key->u.ccmp.tfm, b_0, aad,
 544                                     skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
 545                                     data_len,
 546                                     skb->data + skb->len - mic_len, mic_len))
 547                                 return RX_DROP_UNUSABLE;
 548                 }
 549
 550                 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
 551         }
 552
 553         /* Remove CCMP header and MIC */
 554         if (pskb_trim(skb, skb->len - mic_len))
 555                 return RX_DROP_UNUSABLE;
 556         memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
 557         skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
 558
 559         return RX_CONTINUE;
 560 }
 561
 562 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
 563 {
 564         __le16 mask_fc;
 565         u8 qos_tid;
 566         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 567
 568         memcpy(j_0, hdr->addr2, ETH_ALEN);
 569         memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
 570         j_0[13] = 0;
 571         j_0[14] = 0;
 572         j_0[AES_BLOCK_SIZE - 1] = 0x01;
 573
 574         /* AAD (extra authenticate-only data) / masked 802.11 header
 575          * FC | A1 | A2 | A3 | SC | [A4] | [QC]
 576          */
 577         put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
 578         /* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
 579          * Retry, PwrMgt, MoreData; set Protected
 580          */
 581         mask_fc = hdr->frame_control;
 582         mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
 583                                 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
 584         if (!ieee80211_is_mgmt(hdr->frame_control))
 585                 mask_fc &= ~cpu_to_le16(0x0070);
 586         mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 587
 588         put_unaligned(mask_fc, (__le16 *)&aad[2]);
 589         memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 590
 591         /* Mask Seq#, leave Frag# */
 592         aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
 593         aad[23] = 0;
 594
 595         if (ieee80211_is_data_qos(hdr->frame_control))
 596                 qos_tid = *ieee80211_get_qos_ctl(hdr) &
 597                         IEEE80211_QOS_CTL_TID_MASK;
 598         else
 599                 qos_tid = 0;
 600
 601         if (ieee80211_has_a4(hdr->frame_control)) {
 602                 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
 603                 aad[30] = qos_tid;
 604                 aad[31] = 0;
 605         } else {
 606                 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
 607                 aad[24] = qos_tid;
 608         }
 609 }
 610
 611 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
 612 {
 613         hdr[0] = pn[5];
 614         hdr[1] = pn[4];
 615         hdr[2] = 0;
 616         hdr[3] = 0x20 | (key_id << 6);
 617         hdr[4] = pn[3];
 618         hdr[5] = pn[2];
 619         hdr[6] = pn[1];
 620         hdr[7] = pn[0];
 621 }
 622
 623 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
 624 {
 625         pn[0] = hdr[7];
 626         pn[1] = hdr[6];
 627         pn[2] = hdr[5];
 628         pn[3] = hdr[4];
 629         pn[4] = hdr[1];
 630         pn[5] = hdr[0];
 631 }
 632
 633 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 634 {
 635         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 636         struct ieee80211_key *key = tx->key;
 637         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 638         int hdrlen, len, tail;
 639         u8 *pos;
 640         u8 pn[6];
 641         u64 pn64;
 642         u8 aad[2 * AES_BLOCK_SIZE];
 643         u8 j_0[AES_BLOCK_SIZE];
 644
 645         if (info->control.hw_key &&
 646             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 647             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 648             !((info->control.hw_key->flags &
 649                IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
 650               ieee80211_is_mgmt(hdr->frame_control))) {
 651                 /* hwaccel has no need for preallocated room for GCMP
 652                  * header or MIC fields
 653                  */
 654                 return 0;
 655         }
 656
 657         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 658         len = skb->len - hdrlen;
 659
 660         if (info->control.hw_key)
 661                 tail = 0;
 662         else
 663                 tail = IEEE80211_GCMP_MIC_LEN;
 664
 665         if (WARN_ON(skb_tailroom(skb) < tail ||
 666                     skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
 667                 return -1;
 668
 669         pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
 670         memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
 671         skb_set_network_header(skb, skb_network_offset(skb) +
 672                                     IEEE80211_GCMP_HDR_LEN);
 673
 674         /* the HW only needs room for the IV, but not the actual IV */
 675         if (info->control.hw_key &&
 676             (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 677                 return 0;
 678
 679         hdr = (struct ieee80211_hdr *)pos;
 680         pos += hdrlen;
 681
 682         pn64 = atomic64_inc_return(&key->conf.tx_pn);
 683
 684         pn[5] = pn64;
 685         pn[4] = pn64 >> 8;
 686         pn[3] = pn64 >> 16;
 687         pn[2] = pn64 >> 24;
 688         pn[1] = pn64 >> 32;
 689         pn[0] = pn64 >> 40;
 690
 691         gcmp_pn2hdr(pos, pn, key->conf.keyidx);
 692
 693         /* hwaccel - with software GCMP header */
 694         if (info->control.hw_key)
 695                 return 0;
 696
 697         pos += IEEE80211_GCMP_HDR_LEN;
 698         gcmp_special_blocks(skb, pn, j_0, aad);
 699         ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
 700                                   skb_put(skb, IEEE80211_GCMP_MIC_LEN));
 701
 702         return 0;
 703 }
 704
 705 ieee80211_tx_result
 706 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
 707 {
 708         struct sk_buff *skb;
 709
 710         ieee80211_tx_set_protected(tx);
 711
 712         skb_queue_walk(&tx->skbs, skb) {
 713                 if (gcmp_encrypt_skb(tx, skb) < 0)
 714                         return TX_DROP;
 715         }
 716
 717         return TX_CONTINUE;
 718 }
 719
 720 ieee80211_rx_result
 721 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
 722 {
 723         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 724         int hdrlen;
 725         struct ieee80211_key *key = rx->key;
 726         struct sk_buff *skb = rx->skb;
 727         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 728         u8 pn[IEEE80211_GCMP_PN_LEN];
 729         int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
 730
 731         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 732
 733         if (!ieee80211_is_data(hdr->frame_control) &&
 734             !ieee80211_is_robust_mgmt_frame(skb))
 735                 return RX_CONTINUE;
 736
 737         if (status->flag & RX_FLAG_DECRYPTED) {
 738                 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
 739                         return RX_DROP_UNUSABLE;
 740                 if (status->flag & RX_FLAG_MIC_STRIPPED)
 741                         mic_len = 0;
 742         } else {
 743                 if (skb_linearize(rx->skb))
 744                         return RX_DROP_UNUSABLE;
 745         }
 746
 747         data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
 748         if (!rx->sta || data_len < 0)
 749                 return RX_DROP_UNUSABLE;
 750
 751         if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
 752                 int res;
 753
 754                 gcmp_hdr2pn(pn, skb->data + hdrlen);
 755
 756                 queue = rx->security_idx;
 757
 758                 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
 759                              IEEE80211_GCMP_PN_LEN);
 760                 if (res < 0 ||
 761                     (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
 762                         key->u.gcmp.replays++;
 763                         return RX_DROP_UNUSABLE;
 764                 }
 765
 766                 if (!(status->flag & RX_FLAG_DECRYPTED)) {
 767                         u8 aad[2 * AES_BLOCK_SIZE];
 768                         u8 j_0[AES_BLOCK_SIZE];
 769                         /* hardware didn't decrypt/verify MIC */
 770                         gcmp_special_blocks(skb, pn, j_0, aad);
 771
 772                         if (ieee80211_aes_gcm_decrypt(
 773                                     key->u.gcmp.tfm, j_0, aad,
 774                                     skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
 775                                     data_len,
 776                                     skb->data + skb->len -
 777                                     IEEE80211_GCMP_MIC_LEN))
 778                                 return RX_DROP_UNUSABLE;
 779                 }
 780
 781                 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
 782         }
 783
 784         /* Remove GCMP header and MIC */
 785         if (pskb_trim(skb, skb->len - mic_len))
 786                 return RX_DROP_UNUSABLE;
 787         memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
 788         skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
 789
 790         return RX_CONTINUE;
 791 }
 792
 793 static ieee80211_tx_result
 794 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
 795                             struct sk_buff *skb)
 796 {
 797         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 798         struct ieee80211_key *key = tx->key;
 799         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 800         int hdrlen;
 801         u8 *pos, iv_len = key->conf.iv_len;
 802
 803         if (info->control.hw_key &&
 804             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
 805                 /* hwaccel has no need for preallocated head room */
 806                 return TX_CONTINUE;
 807         }
 808
 809         if (unlikely(skb_headroom(skb) < iv_len &&
 810                      pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
 811                 return TX_DROP;
 812
 813         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 814
 815         pos = skb_push(skb, iv_len);
 816         memmove(pos, pos + iv_len, hdrlen);
 817
 818         return TX_CONTINUE;
 819 }
 820
 821 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
 822 {
 823         int i;
 824
 825         /* pn is little endian */
 826         for (i = len - 1; i >= 0; i--) {
 827                 if (pn1[i] < pn2[i])
 828                         return -1;
 829                 else if (pn1[i] > pn2[i])
 830                         return 1;
 831         }
 832
 833         return 0;
 834 }
 835
 836 static ieee80211_rx_result
 837 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
 838 {
 839         struct ieee80211_key *key = rx->key;
 840         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 841         const struct ieee80211_cipher_scheme *cs = NULL;
 842         int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 843         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 844         int data_len;
 845         u8 *rx_pn;
 846         u8 *skb_pn;
 847         u8 qos_tid;
 848
 849         if (!rx->sta || !rx->sta->cipher_scheme ||
 850             !(status->flag & RX_FLAG_DECRYPTED))
 851                 return RX_DROP_UNUSABLE;
 852
 853         if (!ieee80211_is_data(hdr->frame_control))
 854                 return RX_CONTINUE;
 855
 856         cs = rx->sta->cipher_scheme;
 857
 858         data_len = rx->skb->len - hdrlen - cs->hdr_len;
 859
 860         if (data_len < 0)
 861                 return RX_DROP_UNUSABLE;
 862
 863         if (ieee80211_is_data_qos(hdr->frame_control))
 864                 qos_tid = *ieee80211_get_qos_ctl(hdr) &
 865                                 IEEE80211_QOS_CTL_TID_MASK;
 866         else
 867                 qos_tid = 0;
 868
 869         if (skb_linearize(rx->skb))
 870                 return RX_DROP_UNUSABLE;
 871
 872         hdr = (struct ieee80211_hdr *)rx->skb->data;
 873
 874         rx_pn = key->u.gen.rx_pn[qos_tid];
 875         skb_pn = rx->skb->data + hdrlen + cs->pn_off;
 876
 877         if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
 878                 return RX_DROP_UNUSABLE;
 879
 880         memcpy(rx_pn, skb_pn, cs->pn_len);
 881
 882         /* remove security header and MIC */
 883         if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
 884                 return RX_DROP_UNUSABLE;
 885
 886         memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
 887         skb_pull(rx->skb, cs->hdr_len);
 888
 889         return RX_CONTINUE;
 890 }
 891
 892 static void bip_aad(struct sk_buff *skb, u8 *aad)
 893 {
 894         __le16 mask_fc;
 895         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 896
 897         /* BIP AAD: FC(masked) || A1 || A2 || A3 */
 898
 899         /* FC type/subtype */
 900         /* Mask FC Retry, PwrMgt, MoreData flags to zero */
 901         mask_fc = hdr->frame_control;
 902         mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
 903                                 IEEE80211_FCTL_MOREDATA);
 904         put_unaligned(mask_fc, (__le16 *) &aad[0]);
 905         /* A1 || A2 || A3 */
 906         memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
 907 }
 908
 909
 910 static inline void bip_ipn_set64(u8 *d, u64 pn)
 911 {
 912         *d++ = pn;
 913         *d++ = pn >> 8;
 914         *d++ = pn >> 16;
 915         *d++ = pn >> 24;
 916         *d++ = pn >> 32;
 917         *d = pn >> 40;
 918 }
 919
 920 static inline void bip_ipn_swap(u8 *d, const u8 *s)
 921 {
 922         *d++ = s[5];
 923         *d++ = s[4];
 924         *d++ = s[3];
 925         *d++ = s[2];
 926         *d++ = s[1];
 927         *d = s[0];
 928 }
 929
 930
 931 ieee80211_tx_result
 932 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
 933 {
 934         struct sk_buff *skb;
 935         struct ieee80211_tx_info *info;
 936         struct ieee80211_key *key = tx->key;
 937         struct ieee80211_mmie *mmie;
 938         u8 aad[20];
 939         u64 pn64;
 940
 941         if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
 942                 return TX_DROP;
 943
 944         skb = skb_peek(&tx->skbs);
 945
 946         info = IEEE80211_SKB_CB(skb);
 947
 948         if (info->control.hw_key)
 949                 return TX_CONTINUE;
 950
 951         if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
 952                 return TX_DROP;
 953
 954         mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
 955         mmie->element_id = WLAN_EID_MMIE;
 956         mmie->length = sizeof(*mmie) - 2;
 957         mmie->key_id = cpu_to_le16(key->conf.keyidx);
 958
 959         /* PN = PN + 1 */
 960         pn64 = atomic64_inc_return(&key->conf.tx_pn);
 961
 962         bip_ipn_set64(mmie->sequence_number, pn64);
 963
 964         bip_aad(skb, aad);
 965
 966         /*
 967          * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
 968          */
 969         ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
 970                            skb->data + 24, skb->len - 24, mmie->mic);
 971
 972         return TX_CONTINUE;
 973 }
 974
 975 ieee80211_tx_result
 976 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
 977 {
 978         struct sk_buff *skb;
 979         struct ieee80211_tx_info *info;
 980         struct ieee80211_key *key = tx->key;
 981         struct ieee80211_mmie_16 *mmie;
 982         u8 aad[20];
 983         u64 pn64;
 984
 985         if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
 986                 return TX_DROP;
 987
 988         skb = skb_peek(&tx->skbs);
 989
 990         info = IEEE80211_SKB_CB(skb);
 991
 992         if (info->control.hw_key)
 993                 return TX_CONTINUE;
 994
 995         if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
 996                 return TX_DROP;
 997
 998         mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
 999         mmie->element_id = WLAN_EID_MMIE;
1000         mmie->length = sizeof(*mmie) - 2;
1001         mmie->key_id = cpu_to_le16(key->conf.keyidx);
1002
1003         /* PN = PN + 1 */
1004         pn64 = atomic64_inc_return(&key->conf.tx_pn);
1005
1006         bip_ipn_set64(mmie->sequence_number, pn64);
1007
1008         bip_aad(skb, aad);
1009
1010         /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1011          */
1012         ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1013                                skb->data + 24, skb->len - 24, mmie->mic);
1014
1015         return TX_CONTINUE;
1016 }
1017
1018 ieee80211_rx_result
1019 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1020 {
1021         struct sk_buff *skb = rx->skb;
1022         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1023         struct ieee80211_key *key = rx->key;
1024         struct ieee80211_mmie *mmie;
1025         u8 aad[20], mic[8], ipn[6];
1026         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1027
1028         if (!ieee80211_is_mgmt(hdr->frame_control))
1029                 return RX_CONTINUE;
1030
1031         /* management frames are already linear */
1032
1033         if (skb->len < 24 + sizeof(*mmie))
1034                 return RX_DROP_UNUSABLE;
1035
1036         mmie = (struct ieee80211_mmie *)
1037                 (skb->data + skb->len - sizeof(*mmie));
1038         if (mmie->element_id != WLAN_EID_MMIE ||
1039             mmie->length != sizeof(*mmie) - 2)
1040                 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1041
1042         bip_ipn_swap(ipn, mmie->sequence_number);
1043
1044         if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1045                 key->u.aes_cmac.replays++;
1046                 return RX_DROP_UNUSABLE;
1047         }
1048
1049         if (!(status->flag & RX_FLAG_DECRYPTED)) {
1050                 /* hardware didn't decrypt/verify MIC */
1051                 bip_aad(skb, aad);
1052                 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1053                                    skb->data + 24, skb->len - 24, mic);
1054                 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1055                         key->u.aes_cmac.icverrors++;
1056                         return RX_DROP_UNUSABLE;
1057                 }
1058         }
1059
1060         memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1061
1062         /* Remove MMIE */
1063         skb_trim(skb, skb->len - sizeof(*mmie));
1064
1065         return RX_CONTINUE;
1066 }
1067
1068 ieee80211_rx_result
1069 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1070 {
1071         struct sk_buff *skb = rx->skb;
1072         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1073         struct ieee80211_key *key = rx->key;
1074         struct ieee80211_mmie_16 *mmie;
1075         u8 aad[20], mic[16], ipn[6];
1076         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1077
1078         if (!ieee80211_is_mgmt(hdr->frame_control))
1079                 return RX_CONTINUE;
1080
1081         /* management frames are already linear */
1082
1083         if (skb->len < 24 + sizeof(*mmie))
1084                 return RX_DROP_UNUSABLE;
1085
1086         mmie = (struct ieee80211_mmie_16 *)
1087                 (skb->data + skb->len - sizeof(*mmie));
1088         if (mmie->element_id != WLAN_EID_MMIE ||
1089             mmie->length != sizeof(*mmie) - 2)
1090                 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1091
1092         bip_ipn_swap(ipn, mmie->sequence_number);
1093
1094         if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1095                 key->u.aes_cmac.replays++;
1096                 return RX_DROP_UNUSABLE;
1097         }
1098
1099         if (!(status->flag & RX_FLAG_DECRYPTED)) {
1100                 /* hardware didn't decrypt/verify MIC */
1101                 bip_aad(skb, aad);
1102                 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1103                                        skb->data + 24, skb->len - 24, mic);
1104                 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1105                         key->u.aes_cmac.icverrors++;
1106                         return RX_DROP_UNUSABLE;
1107                 }
1108         }
1109
1110         memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1111
1112         /* Remove MMIE */
1113         skb_trim(skb, skb->len - sizeof(*mmie));
1114
1115         return RX_CONTINUE;
1116 }
1117
1118 ieee80211_tx_result
1119 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1120 {
1121         struct sk_buff *skb;
1122         struct ieee80211_tx_info *info;
1123         struct ieee80211_key *key = tx->key;
1124         struct ieee80211_mmie_16 *mmie;
1125         struct ieee80211_hdr *hdr;
1126         u8 aad[20];
1127         u64 pn64;
1128         u8 nonce[12];
1129
1130         if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1131                 return TX_DROP;
1132
1133         skb = skb_peek(&tx->skbs);
1134
1135         info = IEEE80211_SKB_CB(skb);
1136
1137         if (info->control.hw_key)
1138                 return TX_CONTINUE;
1139
1140         if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1141                 return TX_DROP;
1142
1143         mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
1144         mmie->element_id = WLAN_EID_MMIE;
1145         mmie->length = sizeof(*mmie) - 2;
1146         mmie->key_id = cpu_to_le16(key->conf.keyidx);
1147
1148         /* PN = PN + 1 */
1149         pn64 = atomic64_inc_return(&key->conf.tx_pn);
1150
1151         bip_ipn_set64(mmie->sequence_number, pn64);
1152
1153         bip_aad(skb, aad);
1154
1155         hdr = (struct ieee80211_hdr *)skb->data;
1156         memcpy(nonce, hdr->addr2, ETH_ALEN);
1157         bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1158
1159         /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1160         if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1161                                skb->data + 24, skb->len - 24, mmie->mic) < 0)
1162                 return TX_DROP;
1163
1164         return TX_CONTINUE;
1165 }
1166
1167 ieee80211_rx_result
1168 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1169 {
1170         struct sk_buff *skb = rx->skb;
1171         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1172         struct ieee80211_key *key = rx->key;
1173         struct ieee80211_mmie_16 *mmie;
1174         u8 aad[20], mic[16], ipn[6], nonce[12];
1175         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1176
1177         if (!ieee80211_is_mgmt(hdr->frame_control))
1178                 return RX_CONTINUE;
1179
1180         /* management frames are already linear */
1181
1182         if (skb->len < 24 + sizeof(*mmie))
1183                 return RX_DROP_UNUSABLE;
1184
1185         mmie = (struct ieee80211_mmie_16 *)
1186                 (skb->data + skb->len - sizeof(*mmie));
1187         if (mmie->element_id != WLAN_EID_MMIE ||
1188             mmie->length != sizeof(*mmie) - 2)
1189                 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1190
1191         bip_ipn_swap(ipn, mmie->sequence_number);
1192
1193         if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1194                 key->u.aes_gmac.replays++;
1195                 return RX_DROP_UNUSABLE;
1196         }
1197
1198         if (!(status->flag & RX_FLAG_DECRYPTED)) {
1199                 /* hardware didn't decrypt/verify MIC */
1200                 bip_aad(skb, aad);
1201
1202                 memcpy(nonce, hdr->addr2, ETH_ALEN);
1203                 memcpy(nonce + ETH_ALEN, ipn, 6);
1204
1205                 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1206                                        skb->data + 24, skb->len - 24,
1207                                        mic) < 0 ||
1208                     memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1209                         key->u.aes_gmac.icverrors++;
1210                         return RX_DROP_UNUSABLE;
1211                 }
1212         }
1213
1214         memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1215
1216         /* Remove MMIE */
1217         skb_trim(skb, skb->len - sizeof(*mmie));
1218
1219         return RX_CONTINUE;
1220 }
1221
1222 ieee80211_tx_result
1223 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1224 {
1225         struct sk_buff *skb;
1226         struct ieee80211_tx_info *info = NULL;
1227         ieee80211_tx_result res;
1228
1229         skb_queue_walk(&tx->skbs, skb) {
1230                 info  = IEEE80211_SKB_CB(skb);
1231
1232                 /* handle hw-only algorithm */
1233                 if (!info->control.hw_key)
1234                         return TX_DROP;
1235
1236                 if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1237                         res = ieee80211_crypto_cs_encrypt(tx, skb);
1238                         if (res != TX_CONTINUE)
1239                                 return res;
1240                 }
1241         }
1242
1243         ieee80211_tx_set_protected(tx);
1244
1245         return TX_CONTINUE;
1246 }
1247
1248 ieee80211_rx_result
1249 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1250 {
1251         if (rx->sta && rx->sta->cipher_scheme)
1252                 return ieee80211_crypto_cs_decrypt(rx);
1253
1254         return RX_DROP_UNUSABLE;
1255 }