net/mac80211/wpa.c

   1 /*
   2  * Copyright 2002-2004, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/netdevice.h>
  10 #include <linux/types.h>
  11 #include <linux/slab.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/compiler.h>
  14 #include <net/iw_handler.h>
  15
  16 #include <net/mac80211.h>
  17 #include "ieee80211_common.h"
  18 #include "ieee80211_i.h"
  19 #include "michael.h"
  20 #include "tkip.h"
  21 #include "aes_ccm.h"
  22 #include "wpa.h"
  23
  24 static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
  25                                   u8 *qos_tid, u8 **data, size_t *data_len)
  26 {
  27         struct ieee80211_hdr *hdr;
  28         size_t hdrlen;
  29         u16 fc;
  30         int a4_included;
  31         u8 *pos;
  32
  33         hdr = (struct ieee80211_hdr *) skb->data;
  34         fc = le16_to_cpu(hdr->frame_control);
  35
  36         hdrlen = 24;
  37         if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
  38             (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
  39                 hdrlen += ETH_ALEN;
  40                 *sa = hdr->addr4;
  41                 *da = hdr->addr3;
  42         } else if (fc & IEEE80211_FCTL_FROMDS) {
  43                 *sa = hdr->addr3;
  44                 *da = hdr->addr1;
  45         } else if (fc & IEEE80211_FCTL_TODS) {
  46                 *sa = hdr->addr2;
  47                 *da = hdr->addr3;
  48         } else {
  49                 *sa = hdr->addr2;
  50                 *da = hdr->addr1;
  51         }
  52
  53         if (fc & 0x80)
  54                 hdrlen += 2;
  55
  56         *data = skb->data + hdrlen;
  57         *data_len = skb->len - hdrlen;
  58
  59         a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
  60                 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
  61         if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
  62             fc & IEEE80211_STYPE_QOS_DATA) {
  63                 pos = (u8 *) &hdr->addr4;
  64                 if (a4_included)
  65                         pos += 6;
  66                 *qos_tid = pos[0] & 0x0f;
  67                 *qos_tid |= 0x80; /* qos_included flag */
  68         } else
  69                 *qos_tid = 0;
  70
  71         return skb->len < hdrlen ? -1 : 0;
  72 }
  73
  74
  75 ieee80211_txrx_result
  76 ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
  77 {
  78         u8 *data, *sa, *da, *key, *mic, qos_tid;
  79         size_t data_len;
  80         u16 fc;
  81         struct sk_buff *skb = tx->skb;
  82         int authenticator;
  83         int wpa_test = 0;
  84
  85         fc = tx->fc;
  86
  87         if (!tx->key || tx->key->alg != ALG_TKIP || skb->len < 24 ||
  88             !WLAN_FC_DATA_PRESENT(fc))
  89                 return TXRX_CONTINUE;
  90
  91         if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
  92                 return TXRX_DROP;
  93
  94         if (!tx->key->force_sw_encrypt &&
  95             !tx->fragmented &&
  96             !(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
  97             !wpa_test) {
  98                 /* hwaccel - with no need for preallocated room for Michael MIC
  99                  */
 100                 return TXRX_CONTINUE;
 101         }
 102
 103         if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
 104                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 105                 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
 106                                               MICHAEL_MIC_LEN + TKIP_ICV_LEN,
 107                                               GFP_ATOMIC))) {
 108                         printk(KERN_DEBUG "%s: failed to allocate more memory "
 109                                "for Michael MIC\n", tx->dev->name);
 110                         return TXRX_DROP;
 111                 }
 112         }
 113
 114 #if 0
 115         authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
 116 #else
 117         authenticator = 1;
 118 #endif
 119         key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
 120                             ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
 121         mic = skb_put(skb, MICHAEL_MIC_LEN);
 122         michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
 123
 124         return TXRX_CONTINUE;
 125 }
 126
 127
 128 ieee80211_txrx_result
 129 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
 130 {
 131         u8 *data, *sa, *da, *key = NULL, qos_tid;
 132         size_t data_len;
 133         u16 fc;
 134         u8 mic[MICHAEL_MIC_LEN];
 135         struct sk_buff *skb = rx->skb;
 136         int authenticator = 1, wpa_test = 0;
 137
 138         fc = rx->fc;
 139
 140         /* If device handles decryption totally, skip this check */
 141         if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) ||
 142             (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC))
 143                 return TXRX_CONTINUE;
 144
 145         if (!rx->key || rx->key->alg != ALG_TKIP ||
 146             !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
 147                 return TXRX_CONTINUE;
 148
 149         if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 150             !rx->key->force_sw_encrypt) {
 151                 if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
 152                         if (skb->len < MICHAEL_MIC_LEN)
 153                                 return TXRX_DROP;
 154                 }
 155                 /* Need to verify Michael MIC sometimes in software even when
 156                  * hwaccel is used. Atheros ar5212: fragmented frames and QoS
 157                  * frames. */
 158                 if (!rx->fragmented && !wpa_test)
 159                         goto remove_mic;
 160         }
 161
 162         if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
 163             || data_len < MICHAEL_MIC_LEN)
 164                 return TXRX_DROP;
 165
 166         data_len -= MICHAEL_MIC_LEN;
 167
 168 #if 0
 169         authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
 170 #else
 171         authenticator = 1;
 172 #endif
 173         key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
 174                             ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
 175         michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
 176         if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
 177                 if (!rx->u.rx.ra_match)
 178                         return TXRX_DROP;
 179
 180                 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
 181                        MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));
 182
 183                 do {
 184                         struct ieee80211_hdr *hdr;
 185                         union iwreq_data wrqu;
 186                         char *buf = kmalloc(128, GFP_ATOMIC);
 187                         if (!buf)
 188                                 break;
 189
 190                         /* TODO: needed parameters: count, key type, TSC */
 191                         hdr = (struct ieee80211_hdr *) skb->data;
 192                         sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
 193                                 "keyid=%d %scast addr=" MAC_FMT ")",
 194                                 rx->key->keyidx,
 195                                 hdr->addr1[0] & 0x01 ? "broad" : "uni",
 196                                 MAC_ARG(hdr->addr2));
 197                         memset(&wrqu, 0, sizeof(wrqu));
 198                         wrqu.data.length = strlen(buf);
 199                         wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
 200                         kfree(buf);
 201                 } while (0);
 202
 203                 if (!rx->local->apdev)
 204                         return TXRX_DROP;
 205
 206                 ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
 207                                   ieee80211_msg_michael_mic_failure);
 208
 209                 return TXRX_QUEUED;
 210         }
 211
 212  remove_mic:
 213         /* remove Michael MIC from payload */
 214         skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
 215
 216         return TXRX_CONTINUE;
 217 }
 218
 219
 220 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
 221                             struct sk_buff *skb, int test)
 222 {
 223         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 224         struct ieee80211_key *key = tx->key;
 225         int hdrlen, len, tailneed;
 226         u16 fc;
 227         u8 *pos;
 228
 229         fc = le16_to_cpu(hdr->frame_control);
 230         hdrlen = ieee80211_get_hdrlen(fc);
 231         len = skb->len - hdrlen;
 232
 233         tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN;
 234         if ((skb_headroom(skb) < TKIP_IV_LEN ||
 235              skb_tailroom(skb) < tailneed)) {
 236                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 237                 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
 238                                               GFP_ATOMIC)))
 239                         return -1;
 240         }
 241
 242         pos = skb_push(skb, TKIP_IV_LEN);
 243         memmove(pos, pos + TKIP_IV_LEN, hdrlen);
 244         pos += hdrlen;
 245
 246         /* Increase IV for the frame */
 247         key->u.tkip.iv16++;
 248         if (key->u.tkip.iv16 == 0)
 249                 key->u.tkip.iv32++;
 250
 251         if (!tx->key->force_sw_encrypt) {
 252                 u32 flags = tx->local->hw.flags;
 253                 hdr = (struct ieee80211_hdr *)skb->data;
 254
 255                 /* hwaccel - with preallocated room for IV */
 256                 ieee80211_tkip_add_iv(pos, key,
 257                                       (u8) (key->u.tkip.iv16 >> 8),
 258                                       (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
 259                                             0x7f),
 260                                       (u8) key->u.tkip.iv16);
 261
 262                 if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
 263                         ieee80211_tkip_gen_rc4key(key, hdr->addr2,
 264                                                   tx->u.tx.control->tkip_key);
 265                 else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
 266                         if (key->u.tkip.iv16 == 0 ||
 267                             !key->u.tkip.tx_initialized) {
 268                                 ieee80211_tkip_gen_phase1key(key, hdr->addr2,
 269                                             (u16 *)tx->u.tx.control->tkip_key);
 270                                 key->u.tkip.tx_initialized = 1;
 271                                 tx->u.tx.control->flags |=
 272                                             IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
 273                         } else
 274                                 tx->u.tx.control->flags &=
 275                                             ~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
 276                 }
 277
 278                 tx->u.tx.control->key_idx = tx->key->hw_key_idx;
 279                 return 0;
 280         }
 281
 282         /* Add room for ICV */
 283         skb_put(skb, TKIP_ICV_LEN);
 284
 285         hdr = (struct ieee80211_hdr *) skb->data;
 286         ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
 287                                     key, pos, len, hdr->addr2);
 288         return 0;
 289 }
 290
 291
 292 ieee80211_txrx_result
 293 ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
 294 {
 295         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 296         u16 fc;
 297         struct ieee80211_key *key = tx->key;
 298         struct sk_buff *skb = tx->skb;
 299         int wpa_test = 0, test = 0;
 300
 301         fc = le16_to_cpu(hdr->frame_control);
 302
 303         if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc))
 304                 return TXRX_CONTINUE;
 305
 306         tx->u.tx.control->icv_len = TKIP_ICV_LEN;
 307         tx->u.tx.control->iv_len = TKIP_IV_LEN;
 308         ieee80211_tx_set_iswep(tx);
 309
 310         if (!tx->key->force_sw_encrypt &&
 311             !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
 312             !wpa_test) {
 313                 /* hwaccel - with no need for preallocated room for IV/ICV */
 314                 tx->u.tx.control->key_idx = tx->key->hw_key_idx;
 315                 return TXRX_CONTINUE;
 316         }
 317
 318         if (tkip_encrypt_skb(tx, skb, test) < 0)
 319                 return TXRX_DROP;
 320
 321         if (tx->u.tx.extra_frag) {
 322                 int i;
 323                 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
 324                         if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
 325                             < 0)
 326                                 return TXRX_DROP;
 327                 }
 328         }
 329
 330         return TXRX_CONTINUE;
 331 }
 332
 333
 334 ieee80211_txrx_result
 335 ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx)
 336 {
 337         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 338         u16 fc;
 339         int hdrlen, res, hwaccel = 0, wpa_test = 0;
 340         struct ieee80211_key *key = rx->key;
 341         struct sk_buff *skb = rx->skb;
 342
 343         fc = le16_to_cpu(hdr->frame_control);
 344         hdrlen = ieee80211_get_hdrlen(fc);
 345
 346         if (!rx->key || rx->key->alg != ALG_TKIP ||
 347             !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
 348             (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 349                 return TXRX_CONTINUE;
 350
 351         if (!rx->sta || skb->len - hdrlen < 12)
 352                 return TXRX_DROP;
 353
 354         if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 355             !rx->key->force_sw_encrypt) {
 356                 if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
 357                         /* Hardware takes care of all processing, including
 358                          * replay protection, so no need to continue here. */
 359                         return TXRX_CONTINUE;
 360                 }
 361
 362                 /* let TKIP code verify IV, but skip decryption */
 363                 hwaccel = 1;
 364         }
 365
 366         res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
 367                                           key, skb->data + hdrlen,
 368                                           skb->len - hdrlen, rx->sta->addr,
 369                                           hwaccel, rx->u.rx.queue);
 370         if (res != TKIP_DECRYPT_OK || wpa_test) {
 371                 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
 372                        MAC_FMT " (res=%d)\n",
 373                        rx->dev->name, MAC_ARG(rx->sta->addr), res);
 374                 return TXRX_DROP;
 375         }
 376
 377         /* Trim ICV */
 378         skb_trim(skb, skb->len - TKIP_ICV_LEN);
 379
 380         /* Remove IV */
 381         memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
 382         skb_pull(skb, TKIP_IV_LEN);
 383
 384         return TXRX_CONTINUE;
 385 }
 386
 387
 388 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
 389                                 int encrypted)
 390 {
 391         u16 fc;
 392         int a4_included, qos_included;
 393         u8 qos_tid, *fc_pos, *data, *sa, *da;
 394         int len_a;
 395         size_t data_len;
 396         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 397
 398         fc_pos = (u8 *) &hdr->frame_control;
 399         fc = fc_pos[0] ^ (fc_pos[1] << 8);
 400         a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 401                 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
 402
 403         ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
 404         data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
 405         if (qos_tid & 0x80) {
 406                 qos_included = 1;
 407                 qos_tid &= 0x0f;
 408         } else
 409                 qos_included = 0;
 410         /* First block, b_0 */
 411
 412         b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
 413         /* Nonce: QoS Priority | A2 | PN */
 414         b_0[1] = qos_tid;
 415         memcpy(&b_0[2], hdr->addr2, 6);
 416         memcpy(&b_0[8], pn, CCMP_PN_LEN);
 417         /* l(m) */
 418         b_0[14] = (data_len >> 8) & 0xff;
 419         b_0[15] = data_len & 0xff;
 420
 421
 422         /* AAD (extra authenticate-only data) / masked 802.11 header
 423          * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 424
 425         len_a = a4_included ? 28 : 22;
 426         if (qos_included)
 427                 len_a += 2;
 428
 429         aad[0] = 0; /* (len_a >> 8) & 0xff; */
 430         aad[1] = len_a & 0xff;
 431         /* Mask FC: zero subtype b4 b5 b6 */
 432         aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
 433         /* Retry, PwrMgt, MoreData; set Protected */
 434         aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
 435         memcpy(&aad[4], &hdr->addr1, 18);
 436
 437         /* Mask Seq#, leave Frag# */
 438         aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
 439         aad[23] = 0;
 440         if (a4_included) {
 441                 memcpy(&aad[24], hdr->addr4, 6);
 442                 aad[30] = 0;
 443                 aad[31] = 0;
 444         } else
 445                 memset(&aad[24], 0, 8);
 446         if (qos_included) {
 447                 u8 *dpos = &aad[a4_included ? 30 : 24];
 448
 449                 /* Mask QoS Control field */
 450                 dpos[0] = qos_tid;
 451                 dpos[1] = 0;
 452         }
 453 }
 454
 455
 456 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
 457 {
 458         hdr[0] = pn[5];
 459         hdr[1] = pn[4];
 460         hdr[2] = 0;
 461         hdr[3] = 0x20 | (key_id << 6);
 462         hdr[4] = pn[3];
 463         hdr[5] = pn[2];
 464         hdr[6] = pn[1];
 465         hdr[7] = pn[0];
 466 }
 467
 468
 469 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
 470 {
 471         pn[0] = hdr[7];
 472         pn[1] = hdr[6];
 473         pn[2] = hdr[5];
 474         pn[3] = hdr[4];
 475         pn[4] = hdr[1];
 476         pn[5] = hdr[0];
 477         return (hdr[3] >> 6) & 0x03;
 478 }
 479
 480
 481 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
 482                             struct sk_buff *skb, int test)
 483 {
 484         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 485         struct ieee80211_key *key = tx->key;
 486         int hdrlen, len, tailneed;
 487         u16 fc;
 488         u8 *pos, *pn, *b_0, *aad, *scratch;
 489         int i;
 490
 491         scratch = key->u.ccmp.tx_crypto_buf;
 492         b_0 = scratch + 3 * AES_BLOCK_LEN;
 493         aad = scratch + 4 * AES_BLOCK_LEN;
 494
 495         fc = le16_to_cpu(hdr->frame_control);
 496         hdrlen = ieee80211_get_hdrlen(fc);
 497         len = skb->len - hdrlen;
 498
 499         tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN;
 500
 501         if ((skb_headroom(skb) < CCMP_HDR_LEN ||
 502              skb_tailroom(skb) < tailneed)) {
 503                 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
 504                 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
 505                                               GFP_ATOMIC)))
 506                         return -1;
 507         }
 508
 509         pos = skb_push(skb, CCMP_HDR_LEN);
 510         memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
 511         hdr = (struct ieee80211_hdr *) pos;
 512         pos += hdrlen;
 513
 514         /* PN = PN + 1 */
 515         pn = key->u.ccmp.tx_pn;
 516
 517         for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 518                 pn[i]++;
 519                 if (pn[i])
 520                         break;
 521         }
 522
 523         ccmp_pn2hdr(pos, pn, key->keyidx);
 524
 525         if (!key->force_sw_encrypt) {
 526                 /* hwaccel - with preallocated room for CCMP header */
 527                 tx->u.tx.control->key_idx = key->hw_key_idx;
 528                 return 0;
 529         }
 530
 531         pos += CCMP_HDR_LEN;
 532         ccmp_special_blocks(skb, pn, b_0, aad, 0);
 533         ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
 534                                   pos, skb_put(skb, CCMP_MIC_LEN));
 535
 536         return 0;
 537 }
 538
 539
 540 ieee80211_txrx_result
 541 ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
 542 {
 543         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
 544         struct ieee80211_key *key = tx->key;
 545         u16 fc;
 546         struct sk_buff *skb = tx->skb;
 547         int test = 0;
 548
 549         fc = le16_to_cpu(hdr->frame_control);
 550
 551         if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc))
 552                 return TXRX_CONTINUE;
 553
 554         tx->u.tx.control->icv_len = CCMP_MIC_LEN;
 555         tx->u.tx.control->iv_len = CCMP_HDR_LEN;
 556         ieee80211_tx_set_iswep(tx);
 557
 558         if (!tx->key->force_sw_encrypt &&
 559             !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
 560                 /* hwaccel - with no need for preallocated room for CCMP "
 561                  * header or MIC fields */
 562                 tx->u.tx.control->key_idx = tx->key->hw_key_idx;
 563                 return TXRX_CONTINUE;
 564         }
 565
 566         if (ccmp_encrypt_skb(tx, skb, test) < 0)
 567                 return TXRX_DROP;
 568
 569         if (tx->u.tx.extra_frag) {
 570                 int i;
 571
 572                 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
 573                         if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
 574                             < 0)
 575                                 return TXRX_DROP;
 576                 }
 577         }
 578
 579         return TXRX_CONTINUE;
 580 }
 581
 582
 583 ieee80211_txrx_result
 584 ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx)
 585 {
 586         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 587         u16 fc;
 588         int hdrlen;
 589         struct ieee80211_key *key = rx->key;
 590         struct sk_buff *skb = rx->skb;
 591         u8 pn[CCMP_PN_LEN];
 592         int data_len;
 593
 594         fc = le16_to_cpu(hdr->frame_control);
 595         hdrlen = ieee80211_get_hdrlen(fc);
 596
 597         if (!key || key->alg != ALG_CCMP ||
 598             !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
 599             (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
 600                 return TXRX_CONTINUE;
 601
 602         data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
 603         if (!rx->sta || data_len < 0)
 604                 return TXRX_DROP;
 605
 606         if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 607             !key->force_sw_encrypt &&
 608             !(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
 609                 return TXRX_CONTINUE;
 610
 611         (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
 612
 613         if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
 614 #ifdef CONFIG_MAC80211_DEBUG
 615                 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
 616                 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
 617                        MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
 618                        "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
 619                        MAC_ARG(rx->sta->addr),
 620                        pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
 621                        ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
 622 #endif /* CONFIG_MAC80211_DEBUG */
 623                 key->u.ccmp.replays++;
 624                 return TXRX_DROP;
 625         }
 626
 627         if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 628             !key->force_sw_encrypt) {
 629                 /* hwaccel has already decrypted frame and verified MIC */
 630         } else {
 631                 u8 *scratch, *b_0, *aad;
 632
 633                 scratch = key->u.ccmp.rx_crypto_buf;
 634                 b_0 = scratch + 3 * AES_BLOCK_LEN;
 635                 aad = scratch + 4 * AES_BLOCK_LEN;
 636
 637                 ccmp_special_blocks(skb, pn, b_0, aad, 1);
 638
 639                 if (ieee80211_aes_ccm_decrypt(
 640                             key->u.ccmp.tfm, scratch, b_0, aad,
 641                             skb->data + hdrlen + CCMP_HDR_LEN, data_len,
 642                             skb->data + skb->len - CCMP_MIC_LEN,
 643                             skb->data + hdrlen + CCMP_HDR_LEN)) {
 644                         printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
 645                                "frame from " MAC_FMT "\n", rx->dev->name,
 646                                MAC_ARG(rx->sta->addr));
 647                         return TXRX_DROP;
 648                 }
 649         }
 650
 651         memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
 652
 653         /* Remove CCMP header and MIC */
 654         skb_trim(skb, skb->len - CCMP_MIC_LEN);
 655         memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
 656         skb_pull(skb, CCMP_HDR_LEN);
 657
 658         return TXRX_CONTINUE;
 659 }
 660