net/mac80211/wpa.c

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