net/mac80211/wpa.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
ieee80211_tx_h_michael_mic_add
ieee80211_rx_h_michael_mic_verify
tkip_encrypt_skb
ieee80211_crypto_tkip_encrypt
ieee80211_crypto_tkip_decrypt
ccmp_special_blocks
ccmp_pn2hdr
ccmp_hdr2pn
ccmp_encrypt_skb
ieee80211_crypto_ccmp_encrypt
ieee80211_crypto_ccmp_decrypt
gcmp_special_blocks
gcmp_pn2hdr
gcmp_hdr2pn
gcmp_encrypt_skb
ieee80211_crypto_gcmp_encrypt
ieee80211_crypto_gcmp_decrypt
ieee80211_crypto_cs_encrypt
ieee80211_crypto_cs_pn_compare
ieee80211_crypto_cs_decrypt
bip_aad
bip_ipn_set64
bip_ipn_swap
ieee80211_crypto_aes_cmac_encrypt
ieee80211_crypto_aes_cmac_256_encrypt
ieee80211_crypto_aes_cmac_decrypt
ieee80211_crypto_aes_cmac_256_decrypt
ieee80211_crypto_aes_gmac_encrypt
ieee80211_crypto_aes_gmac_decrypt
ieee80211_crypto_hw_encrypt
ieee80211_crypto_hw_decrypt
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2002-2004, Instant802 Networks, Inc.
   4  * Copyright 2008, Jouni Malinen <j@w1.fi>
   5  * Copyright (C) 2016-2017 Intel Deutschland GmbH
   6  */
   7 
   8 #include <linux/netdevice.h>
   9 #include <linux/types.h>
  10 #include <linux/skbuff.h>
  11 #include <linux/compiler.h>
  12 #include <linux/ieee80211.h>
  13 #include <linux/gfp.h>
  14 #include <asm/unaligned.h>
  15 #include <net/mac80211.h>
  16 #include <crypto/aes.h>
  17 #include <crypto/algapi.h>
  18 
  19 #include "ieee80211_i.h"
  20 #include "michael.h"
  21 #include "tkip.h"
  22 #include "aes_ccm.h"
  23 #include "aes_cmac.h"
  24 #include "aes_gmac.h"
  25 #include "aes_gcm.h"
  26 #include "wpa.h"
  27 
  28 ieee80211_tx_result
  29 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
  30 {
  31         u8 *data, *key, *mic;
  32         size_t data_len;
  33         unsigned int hdrlen;
  34         struct ieee80211_hdr *hdr;
  35         struct sk_buff *skb = tx->skb;
  36         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  37         int tail;
  38 
  39         hdr = (struct ieee80211_hdr *)skb->data;
  40         if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
  41             skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
  42                 return TX_CONTINUE;
  43 
  44         hdrlen = ieee80211_hdrlen(hdr->frame_control);
  45         if (skb->len < hdrlen)
  46                 return TX_DROP;
  47 
  48         data = skb->data + hdrlen;
  49         data_len = skb->len - hdrlen;
  50 
  51         if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
  52                 /* Need to use software crypto for the test */
  53                 info->control.hw_key = NULL;
  54         }
  55 
  56         if (info->control.hw_key &&
  57             (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
  58              ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) &&
  59             !(tx->key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
  60                                      IEEE80211_KEY_FLAG_PUT_MIC_SPACE))) {
  61                 /* hwaccel - with no need for SW-generated MMIC or MIC space */
  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         mic = skb_put(skb, MICHAEL_MIC_LEN);
  77 
  78         if (tx->key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) {
  79                 /* Zeroed MIC can help with debug */
  80                 memset(mic, 0, MICHAEL_MIC_LEN);
  81                 return TX_CONTINUE;
  82         }
  83 
  84         key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
  85         michael_mic(key, hdr, data, data_len, mic);
  86         if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
  87                 mic[0]++;
  88 
  89         return TX_CONTINUE;
  90 }
  91 
  92 
  93 ieee80211_rx_result
  94 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
  95 {
  96         u8 *data, *key = NULL;
  97         size_t data_len;
  98         unsigned int hdrlen;
  99         u8 mic[MICHAEL_MIC_LEN];
 100         struct sk_buff *skb = rx->skb;
 101         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 102         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 103 
 104         /*
 105          * it makes no sense to check for MIC errors on anything other
 106          * than data frames.
 107          */
 108         if (!ieee80211_is_data_present(hdr->frame_control))
 109                 return RX_CONTINUE;
 110 
 111         /*
 112          * No way to verify the MIC if the hardware stripped it or
 113          * the IV with the key index. In this case we have solely rely
 114          * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
 115          * MIC failure report.
 116          */
 117         if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
 118                 if (status->flag & RX_FLAG_MMIC_ERROR)
 119                         goto mic_fail_no_key;
 120 
 121                 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
 122                     rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
 123                         goto update_iv;
 124 
 125                 return RX_CONTINUE;
 126         }
 127 
 128         /*
 129          * Some hardware seems to generate Michael MIC failure reports; even
 130          * though, the frame was not encrypted with TKIP and therefore has no
 131          * MIC. Ignore the flag them to avoid triggering countermeasures.
 132          */
 133         if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
 134             !(status->flag & RX_FLAG_DECRYPTED))
 135                 return RX_CONTINUE;
 136 
 137         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
 138                 /*
 139                  * APs with pairwise keys should never receive Michael MIC
 140                  * errors for non-zero keyidx because these are reserved for
 141                  * group keys and only the AP is sending real multicast
 142                  * frames in the BSS.
 143                  */
 144                 return RX_DROP_UNUSABLE;
 145         }
 146 
 147         if (status->flag & RX_FLAG_MMIC_ERROR)
 148                 goto mic_fail;
 149 
 150         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 151         if (skb->len < hdrlen + MICHAEL_MIC_LEN)
 152                 return RX_DROP_UNUSABLE;
 153 
 154         if (skb_linearize(rx->skb))
 155                 return RX_DROP_UNUSABLE;
 156         hdr = (void *)skb->data;
 157 
 158         data = skb->data + hdrlen;
 159         data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
 160         key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
 161         michael_mic(key, hdr, data, data_len, mic);
 162         if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN))
 163                 goto mic_fail;
 164 
 165         /* remove Michael MIC from payload */
 166         skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
 167 
 168 update_iv:
 169         /* update IV in key information to be able to detect replays */
 170         rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
 171         rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
 172 
 173         return RX_CONTINUE;
 174 
 175 mic_fail:
 176         rx->key->u.tkip.mic_failures++;
 177 
 178 mic_fail_no_key:
 179         /*
 180          * In some cases the key can be unset - e.g. a multicast packet, in
 181          * a driver that supports HW encryption. Send up the key idx only if
 182          * the key is set.
 183          */
 184         cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
 185                                      is_multicast_ether_addr(hdr->addr1) ?
 186                                      NL80211_KEYTYPE_GROUP :
 187                                      NL80211_KEYTYPE_PAIRWISE,
 188                                      rx->key ? rx->key->conf.keyidx : -1,
 189                                      NULL, GFP_ATOMIC);
 190         return RX_DROP_UNUSABLE;
 191 }
 192 
 193 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 194 {
 195         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 196         struct ieee80211_key *key = tx->key;
 197         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 198         unsigned int hdrlen;
 199         int len, tail;
 200         u64 pn;
 201         u8 *pos;
 202 
 203         if (info->control.hw_key &&
 204             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 205             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
 206                 /* hwaccel - with no need for software-generated IV */
 207                 return 0;
 208         }
 209 
 210         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 211         len = skb->len - hdrlen;
 212 
 213         if (info->control.hw_key)
 214                 tail = 0;
 215         else
 216                 tail = IEEE80211_TKIP_ICV_LEN;
 217 
 218         if (WARN_ON(skb_tailroom(skb) < tail ||
 219                     skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
 220                 return -1;
 221 
 222         pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
 223         memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
 224         pos += hdrlen;
 225 
 226         /* the HW only needs room for the IV, but not the actual IV */
 227         if (info->control.hw_key &&
 228             (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 229                 return 0;
 230 
 231         /* Increase IV for the frame */
 232         pn = atomic64_inc_return(&key->conf.tx_pn);
 233         pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
 234 
 235         /* hwaccel - with software IV */
 236         if (info->control.hw_key)
 237                 return 0;
 238 
 239         /* Add room for ICV */
 240         skb_put(skb, IEEE80211_TKIP_ICV_LEN);
 241 
 242         return ieee80211_tkip_encrypt_data(&tx->local->wep_tx_ctx,
 243                                            key, skb, pos, len);
 244 }
 245 
 246 
 247 ieee80211_tx_result
 248 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
 249 {
 250         struct sk_buff *skb;
 251 
 252         ieee80211_tx_set_protected(tx);
 253 
 254         skb_queue_walk(&tx->skbs, skb) {
 255                 if (tkip_encrypt_skb(tx, skb) < 0)
 256                         return TX_DROP;
 257         }
 258 
 259         return TX_CONTINUE;
 260 }
 261 
 262 
 263 ieee80211_rx_result
 264 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 265 {
 266         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 267         int hdrlen, res, hwaccel = 0;
 268         struct ieee80211_key *key = rx->key;
 269         struct sk_buff *skb = rx->skb;
 270         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 271 
 272         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 273 
 274         if (!ieee80211_is_data(hdr->frame_control))
 275                 return RX_CONTINUE;
 276 
 277         if (!rx->sta || skb->len - hdrlen < 12)
 278                 return RX_DROP_UNUSABLE;
 279 
 280         /* it may be possible to optimize this a bit more */
 281         if (skb_linearize(rx->skb))
 282                 return RX_DROP_UNUSABLE;
 283         hdr = (void *)skb->data;
 284 
 285         /*
 286          * Let TKIP code verify IV, but skip decryption.
 287          * In the case where hardware checks the IV as well,
 288          * we don't even get here, see ieee80211_rx_h_decrypt()
 289          */
 290         if (status->flag & RX_FLAG_DECRYPTED)
 291                 hwaccel = 1;
 292 
 293         res = ieee80211_tkip_decrypt_data(&rx->local->wep_rx_ctx,
 294                                           key, skb->data + hdrlen,
 295                                           skb->len - hdrlen, rx->sta->sta.addr,
 296                                           hdr->addr1, hwaccel, rx->security_idx,
 297                                           &rx->tkip_iv32,
 298                                           &rx->tkip_iv16);
 299         if (res != TKIP_DECRYPT_OK)
 300                 return RX_DROP_UNUSABLE;
 301 
 302         /* Trim ICV */
 303         if (!(status->flag & RX_FLAG_ICV_STRIPPED))
 304                 skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
 305 
 306         /* Remove IV */
 307         memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
 308         skb_pull(skb, IEEE80211_TKIP_IV_LEN);
 309 
 310         return RX_CONTINUE;
 311 }
 312 
 313 
 314 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
 315 {
 316         __le16 mask_fc;
 317         int a4_included, mgmt;
 318         u8 qos_tid;
 319         u16 len_a;
 320         unsigned int hdrlen;
 321         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 322 
 323         /*
 324          * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
 325          * Retry, PwrMgt, MoreData; set Protected
 326          */
 327         mgmt = ieee80211_is_mgmt(hdr->frame_control);
 328         mask_fc = hdr->frame_control;
 329         mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
 330                                 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
 331         if (!mgmt)
 332                 mask_fc &= ~cpu_to_le16(0x0070);
 333         mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 334 
 335         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 336         len_a = hdrlen - 2;
 337         a4_included = ieee80211_has_a4(hdr->frame_control);
 338 
 339         if (ieee80211_is_data_qos(hdr->frame_control))
 340                 qos_tid = ieee80211_get_tid(hdr);
 341         else
 342                 qos_tid = 0;
 343 
 344         /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
 345          * mode authentication are not allowed to collide, yet both are derived
 346          * from this vector b_0. We only set L := 1 here to indicate that the
 347          * data size can be represented in (L+1) bytes. The CCM layer will take
 348          * care of storing the data length in the top (L+1) bytes and setting
 349          * and clearing the other bits as is required to derive the two IVs.
 350          */
 351         b_0[0] = 0x1;
 352 
 353         /* Nonce: Nonce Flags | A2 | PN
 354          * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
 355          */
 356         b_0[1] = qos_tid | (mgmt << 4);
 357         memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
 358         memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
 359 
 360         /* AAD (extra authenticate-only data) / masked 802.11 header
 361          * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 362         put_unaligned_be16(len_a, &aad[0]);
 363         put_unaligned(mask_fc, (__le16 *)&aad[2]);
 364         memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 365 
 366         /* Mask Seq#, leave Frag# */
 367         aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
 368         aad[23] = 0;
 369 
 370         if (a4_included) {
 371                 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
 372                 aad[30] = qos_tid;
 373                 aad[31] = 0;
 374         } else {
 375                 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
 376                 aad[24] = qos_tid;
 377         }
 378 }
 379 
 380 
 381 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
 382 {
 383         hdr[0] = pn[5];
 384         hdr[1] = pn[4];
 385         hdr[2] = 0;
 386         hdr[3] = 0x20 | (key_id << 6);
 387         hdr[4] = pn[3];
 388         hdr[5] = pn[2];
 389         hdr[6] = pn[1];
 390         hdr[7] = pn[0];
 391 }
 392 
 393 
 394 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
 395 {
 396         pn[0] = hdr[7];
 397         pn[1] = hdr[6];
 398         pn[2] = hdr[5];
 399         pn[3] = hdr[4];
 400         pn[4] = hdr[1];
 401         pn[5] = hdr[0];
 402 }
 403 
 404 
 405 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
 406                             unsigned int mic_len)
 407 {
 408         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 409         struct ieee80211_key *key = tx->key;
 410         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 411         int hdrlen, len, tail;
 412         u8 *pos;
 413         u8 pn[6];
 414         u64 pn64;
 415         u8 aad[CCM_AAD_LEN];
 416         u8 b_0[AES_BLOCK_SIZE];
 417 
 418         if (info->control.hw_key &&
 419             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 420             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 421             !((info->control.hw_key->flags &
 422                IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
 423               ieee80211_is_mgmt(hdr->frame_control))) {
 424                 /*
 425                  * hwaccel has no need for preallocated room for CCMP
 426                  * header or MIC fields
 427                  */
 428                 return 0;
 429         }
 430 
 431         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 432         len = skb->len - hdrlen;
 433 
 434         if (info->control.hw_key)
 435                 tail = 0;
 436         else
 437                 tail = mic_len;
 438 
 439         if (WARN_ON(skb_tailroom(skb) < tail ||
 440                     skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
 441                 return -1;
 442 
 443         pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
 444         memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
 445 
 446         /* the HW only needs room for the IV, but not the actual IV */
 447         if (info->control.hw_key &&
 448             (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 449                 return 0;
 450 
 451         hdr = (struct ieee80211_hdr *) pos;
 452         pos += hdrlen;
 453 
 454         pn64 = atomic64_inc_return(&key->conf.tx_pn);
 455 
 456         pn[5] = pn64;
 457         pn[4] = pn64 >> 8;
 458         pn[3] = pn64 >> 16;
 459         pn[2] = pn64 >> 24;
 460         pn[1] = pn64 >> 32;
 461         pn[0] = pn64 >> 40;
 462 
 463         ccmp_pn2hdr(pos, pn, key->conf.keyidx);
 464 
 465         /* hwaccel - with software CCMP header */
 466         if (info->control.hw_key)
 467                 return 0;
 468 
 469         pos += IEEE80211_CCMP_HDR_LEN;
 470         ccmp_special_blocks(skb, pn, b_0, aad);
 471         return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
 472                                          skb_put(skb, mic_len));
 473 }
 474 
 475 
 476 ieee80211_tx_result
 477 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
 478                               unsigned int mic_len)
 479 {
 480         struct sk_buff *skb;
 481 
 482         ieee80211_tx_set_protected(tx);
 483 
 484         skb_queue_walk(&tx->skbs, skb) {
 485                 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
 486                         return TX_DROP;
 487         }
 488 
 489         return TX_CONTINUE;
 490 }
 491 
 492 
 493 ieee80211_rx_result
 494 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
 495                               unsigned int mic_len)
 496 {
 497         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 498         int hdrlen;
 499         struct ieee80211_key *key = rx->key;
 500         struct sk_buff *skb = rx->skb;
 501         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 502         u8 pn[IEEE80211_CCMP_PN_LEN];
 503         int data_len;
 504         int queue;
 505 
 506         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 507 
 508         if (!ieee80211_is_data(hdr->frame_control) &&
 509             !ieee80211_is_robust_mgmt_frame(skb))
 510                 return RX_CONTINUE;
 511 
 512         if (status->flag & RX_FLAG_DECRYPTED) {
 513                 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
 514                         return RX_DROP_UNUSABLE;
 515                 if (status->flag & RX_FLAG_MIC_STRIPPED)
 516                         mic_len = 0;
 517         } else {
 518                 if (skb_linearize(rx->skb))
 519                         return RX_DROP_UNUSABLE;
 520         }
 521 
 522         data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
 523         if (!rx->sta || data_len < 0)
 524                 return RX_DROP_UNUSABLE;
 525 
 526         if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
 527                 int res;
 528 
 529                 ccmp_hdr2pn(pn, skb->data + hdrlen);
 530 
 531                 queue = rx->security_idx;
 532 
 533                 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
 534                              IEEE80211_CCMP_PN_LEN);
 535                 if (res < 0 ||
 536                     (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
 537                         key->u.ccmp.replays++;
 538                         return RX_DROP_UNUSABLE;
 539                 }
 540 
 541                 if (!(status->flag & RX_FLAG_DECRYPTED)) {
 542                         u8 aad[2 * AES_BLOCK_SIZE];
 543                         u8 b_0[AES_BLOCK_SIZE];
 544                         /* hardware didn't decrypt/verify MIC */
 545                         ccmp_special_blocks(skb, pn, b_0, aad);
 546 
 547                         if (ieee80211_aes_ccm_decrypt(
 548                                     key->u.ccmp.tfm, b_0, aad,
 549                                     skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
 550                                     data_len,
 551                                     skb->data + skb->len - mic_len))
 552                                 return RX_DROP_UNUSABLE;
 553                 }
 554 
 555                 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
 556         }
 557 
 558         /* Remove CCMP header and MIC */
 559         if (pskb_trim(skb, skb->len - mic_len))
 560                 return RX_DROP_UNUSABLE;
 561         memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
 562         skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
 563 
 564         return RX_CONTINUE;
 565 }
 566 
 567 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
 568 {
 569         __le16 mask_fc;
 570         u8 qos_tid;
 571         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 572 
 573         memcpy(j_0, hdr->addr2, ETH_ALEN);
 574         memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
 575         j_0[13] = 0;
 576         j_0[14] = 0;
 577         j_0[AES_BLOCK_SIZE - 1] = 0x01;
 578 
 579         /* AAD (extra authenticate-only data) / masked 802.11 header
 580          * FC | A1 | A2 | A3 | SC | [A4] | [QC]
 581          */
 582         put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
 583         /* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
 584          * Retry, PwrMgt, MoreData; set Protected
 585          */
 586         mask_fc = hdr->frame_control;
 587         mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
 588                                 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
 589         if (!ieee80211_is_mgmt(hdr->frame_control))
 590                 mask_fc &= ~cpu_to_le16(0x0070);
 591         mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 592 
 593         put_unaligned(mask_fc, (__le16 *)&aad[2]);
 594         memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 595 
 596         /* Mask Seq#, leave Frag# */
 597         aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
 598         aad[23] = 0;
 599 
 600         if (ieee80211_is_data_qos(hdr->frame_control))
 601                 qos_tid = ieee80211_get_tid(hdr);
 602         else
 603                 qos_tid = 0;
 604 
 605         if (ieee80211_has_a4(hdr->frame_control)) {
 606                 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
 607                 aad[30] = qos_tid;
 608                 aad[31] = 0;
 609         } else {
 610                 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
 611                 aad[24] = qos_tid;
 612         }
 613 }
 614 
 615 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
 616 {
 617         hdr[0] = pn[5];
 618         hdr[1] = pn[4];
 619         hdr[2] = 0;
 620         hdr[3] = 0x20 | (key_id << 6);
 621         hdr[4] = pn[3];
 622         hdr[5] = pn[2];
 623         hdr[6] = pn[1];
 624         hdr[7] = pn[0];
 625 }
 626 
 627 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
 628 {
 629         pn[0] = hdr[7];
 630         pn[1] = hdr[6];
 631         pn[2] = hdr[5];
 632         pn[3] = hdr[4];
 633         pn[4] = hdr[1];
 634         pn[5] = hdr[0];
 635 }
 636 
 637 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 638 {
 639         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 640         struct ieee80211_key *key = tx->key;
 641         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 642         int hdrlen, len, tail;
 643         u8 *pos;
 644         u8 pn[6];
 645         u64 pn64;
 646         u8 aad[GCM_AAD_LEN];
 647         u8 j_0[AES_BLOCK_SIZE];
 648 
 649         if (info->control.hw_key &&
 650             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 651             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 652             !((info->control.hw_key->flags &
 653                IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
 654               ieee80211_is_mgmt(hdr->frame_control))) {
 655                 /* hwaccel has no need for preallocated room for GCMP
 656                  * header or MIC fields
 657                  */
 658                 return 0;
 659         }
 660 
 661         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 662         len = skb->len - hdrlen;
 663 
 664         if (info->control.hw_key)
 665                 tail = 0;
 666         else
 667                 tail = IEEE80211_GCMP_MIC_LEN;
 668 
 669         if (WARN_ON(skb_tailroom(skb) < tail ||
 670                     skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
 671                 return -1;
 672 
 673         pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
 674         memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
 675         skb_set_network_header(skb, skb_network_offset(skb) +
 676                                     IEEE80211_GCMP_HDR_LEN);
 677 
 678         /* the HW only needs room for the IV, but not the actual IV */
 679         if (info->control.hw_key &&
 680             (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 681                 return 0;
 682 
 683         hdr = (struct ieee80211_hdr *)pos;
 684         pos += hdrlen;
 685 
 686         pn64 = atomic64_inc_return(&key->conf.tx_pn);
 687 
 688         pn[5] = pn64;
 689         pn[4] = pn64 >> 8;
 690         pn[3] = pn64 >> 16;
 691         pn[2] = pn64 >> 24;
 692         pn[1] = pn64 >> 32;
 693         pn[0] = pn64 >> 40;
 694 
 695         gcmp_pn2hdr(pos, pn, key->conf.keyidx);
 696 
 697         /* hwaccel - with software GCMP header */
 698         if (info->control.hw_key)
 699                 return 0;
 700 
 701         pos += IEEE80211_GCMP_HDR_LEN;
 702         gcmp_special_blocks(skb, pn, j_0, aad);
 703         return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
 704                                          skb_put(skb, IEEE80211_GCMP_MIC_LEN));
 705 }
 706 
 707 ieee80211_tx_result
 708 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
 709 {
 710         struct sk_buff *skb;
 711 
 712         ieee80211_tx_set_protected(tx);
 713 
 714         skb_queue_walk(&tx->skbs, skb) {
 715                 if (gcmp_encrypt_skb(tx, skb) < 0)
 716                         return TX_DROP;
 717         }
 718 
 719         return TX_CONTINUE;
 720 }
 721 
 722 ieee80211_rx_result
 723 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
 724 {
 725         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 726         int hdrlen;
 727         struct ieee80211_key *key = rx->key;
 728         struct sk_buff *skb = rx->skb;
 729         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 730         u8 pn[IEEE80211_GCMP_PN_LEN];
 731         int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
 732 
 733         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 734 
 735         if (!ieee80211_is_data(hdr->frame_control) &&
 736             !ieee80211_is_robust_mgmt_frame(skb))
 737                 return RX_CONTINUE;
 738 
 739         if (status->flag & RX_FLAG_DECRYPTED) {
 740                 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
 741                         return RX_DROP_UNUSABLE;
 742                 if (status->flag & RX_FLAG_MIC_STRIPPED)
 743                         mic_len = 0;
 744         } else {
 745                 if (skb_linearize(rx->skb))
 746                         return RX_DROP_UNUSABLE;
 747         }
 748 
 749         data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
 750         if (!rx->sta || data_len < 0)
 751                 return RX_DROP_UNUSABLE;
 752 
 753         if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
 754                 int res;
 755 
 756                 gcmp_hdr2pn(pn, skb->data + hdrlen);
 757 
 758                 queue = rx->security_idx;
 759 
 760                 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
 761                              IEEE80211_GCMP_PN_LEN);
 762                 if (res < 0 ||
 763                     (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
 764                         key->u.gcmp.replays++;
 765                         return RX_DROP_UNUSABLE;
 766                 }
 767 
 768                 if (!(status->flag & RX_FLAG_DECRYPTED)) {
 769                         u8 aad[2 * AES_BLOCK_SIZE];
 770                         u8 j_0[AES_BLOCK_SIZE];
 771                         /* hardware didn't decrypt/verify MIC */
 772                         gcmp_special_blocks(skb, pn, j_0, aad);
 773 
 774                         if (ieee80211_aes_gcm_decrypt(
 775                                     key->u.gcmp.tfm, j_0, aad,
 776                                     skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
 777                                     data_len,
 778                                     skb->data + skb->len -
 779                                     IEEE80211_GCMP_MIC_LEN))
 780                                 return RX_DROP_UNUSABLE;
 781                 }
 782 
 783                 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
 784         }
 785 
 786         /* Remove GCMP header and MIC */
 787         if (pskb_trim(skb, skb->len - mic_len))
 788                 return RX_DROP_UNUSABLE;
 789         memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
 790         skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
 791 
 792         return RX_CONTINUE;
 793 }
 794 
 795 static ieee80211_tx_result
 796 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
 797                             struct sk_buff *skb)
 798 {
 799         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 800         struct ieee80211_key *key = tx->key;
 801         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 802         int hdrlen;
 803         u8 *pos, iv_len = key->conf.iv_len;
 804 
 805         if (info->control.hw_key &&
 806             !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
 807                 /* hwaccel has no need for preallocated head room */
 808                 return TX_CONTINUE;
 809         }
 810 
 811         if (unlikely(skb_headroom(skb) < iv_len &&
 812                      pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
 813                 return TX_DROP;
 814 
 815         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 816 
 817         pos = skb_push(skb, iv_len);
 818         memmove(pos, pos + iv_len, hdrlen);
 819 
 820         return TX_CONTINUE;
 821 }
 822 
 823 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
 824 {
 825         int i;
 826 
 827         /* pn is little endian */
 828         for (i = len - 1; i >= 0; i--) {
 829                 if (pn1[i] < pn2[i])
 830                         return -1;
 831                 else if (pn1[i] > pn2[i])
 832                         return 1;
 833         }
 834 
 835         return 0;
 836 }
 837 
 838 static ieee80211_rx_result
 839 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
 840 {
 841         struct ieee80211_key *key = rx->key;
 842         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 843         const struct ieee80211_cipher_scheme *cs = NULL;
 844         int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 845         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 846         int data_len;
 847         u8 *rx_pn;
 848         u8 *skb_pn;
 849         u8 qos_tid;
 850 
 851         if (!rx->sta || !rx->sta->cipher_scheme ||
 852             !(status->flag & RX_FLAG_DECRYPTED))
 853                 return RX_DROP_UNUSABLE;
 854 
 855         if (!ieee80211_is_data(hdr->frame_control))
 856                 return RX_CONTINUE;
 857 
 858         cs = rx->sta->cipher_scheme;
 859 
 860         data_len = rx->skb->len - hdrlen - cs->hdr_len;
 861 
 862         if (data_len < 0)
 863                 return RX_DROP_UNUSABLE;
 864 
 865         if (ieee80211_is_data_qos(hdr->frame_control))
 866                 qos_tid = ieee80211_get_tid(hdr);
 867         else
 868                 qos_tid = 0;
 869 
 870         if (skb_linearize(rx->skb))
 871                 return RX_DROP_UNUSABLE;
 872 
 873         hdr = (struct ieee80211_hdr *)rx->skb->data;
 874 
 875         rx_pn = key->u.gen.rx_pn[qos_tid];
 876         skb_pn = rx->skb->data + hdrlen + cs->pn_off;
 877 
 878         if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
 879                 return RX_DROP_UNUSABLE;
 880 
 881         memcpy(rx_pn, skb_pn, cs->pn_len);
 882 
 883         /* remove security header and MIC */
 884         if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
 885                 return RX_DROP_UNUSABLE;
 886 
 887         memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
 888         skb_pull(rx->skb, cs->hdr_len);
 889 
 890         return RX_CONTINUE;
 891 }
 892 
 893 static void bip_aad(struct sk_buff *skb, u8 *aad)
 894 {
 895         __le16 mask_fc;
 896         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 897 
 898         /* BIP AAD: FC(masked) || A1 || A2 || A3 */
 899 
 900         /* FC type/subtype */
 901         /* Mask FC Retry, PwrMgt, MoreData flags to zero */
 902         mask_fc = hdr->frame_control;
 903         mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
 904                                 IEEE80211_FCTL_MOREDATA);
 905         put_unaligned(mask_fc, (__le16 *) &aad[0]);
 906         /* A1 || A2 || A3 */
 907         memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
 908 }
 909 
 910 
 911 static inline void bip_ipn_set64(u8 *d, u64 pn)
 912 {
 913         *d++ = pn;
 914         *d++ = pn >> 8;
 915         *d++ = pn >> 16;
 916         *d++ = pn >> 24;
 917         *d++ = pn >> 32;
 918         *d = pn >> 40;
 919 }
 920 
 921 static inline void bip_ipn_swap(u8 *d, const u8 *s)
 922 {
 923         *d++ = s[5];
 924         *d++ = s[4];
 925         *d++ = s[3];
 926         *d++ = s[2];
 927         *d++ = s[1];
 928         *d = s[0];
 929 }
 930 
 931 
 932 ieee80211_tx_result
 933 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
 934 {
 935         struct sk_buff *skb;
 936         struct ieee80211_tx_info *info;
 937         struct ieee80211_key *key = tx->key;
 938         struct ieee80211_mmie *mmie;
 939         u8 aad[20];
 940         u64 pn64;
 941 
 942         if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
 943                 return TX_DROP;
 944 
 945         skb = skb_peek(&tx->skbs);
 946 
 947         info = IEEE80211_SKB_CB(skb);
 948 
 949         if (info->control.hw_key &&
 950             !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
 951                 return TX_CONTINUE;
 952 
 953         if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
 954                 return TX_DROP;
 955 
 956         mmie = skb_put(skb, sizeof(*mmie));
 957         mmie->element_id = WLAN_EID_MMIE;
 958         mmie->length = sizeof(*mmie) - 2;
 959         mmie->key_id = cpu_to_le16(key->conf.keyidx);
 960 
 961         /* PN = PN + 1 */
 962         pn64 = atomic64_inc_return(&key->conf.tx_pn);
 963 
 964         bip_ipn_set64(mmie->sequence_number, pn64);
 965 
 966         if (info->control.hw_key)
 967                 return TX_CONTINUE;
 968 
 969         bip_aad(skb, aad);
 970 
 971         /*
 972          * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
 973          */
 974         ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
 975                            skb->data + 24, skb->len - 24, mmie->mic);
 976 
 977         return TX_CONTINUE;
 978 }
 979 
 980 ieee80211_tx_result
 981 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
 982 {
 983         struct sk_buff *skb;
 984         struct ieee80211_tx_info *info;
 985         struct ieee80211_key *key = tx->key;
 986         struct ieee80211_mmie_16 *mmie;
 987         u8 aad[20];
 988         u64 pn64;
 989 
 990         if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
 991                 return TX_DROP;
 992 
 993         skb = skb_peek(&tx->skbs);
 994 
 995         info = IEEE80211_SKB_CB(skb);
 996 
 997         if (info->control.hw_key)
 998                 return TX_CONTINUE;
 999 
1000         if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1001                 return TX_DROP;
1002 
1003         mmie = skb_put(skb, sizeof(*mmie));
1004         mmie->element_id = WLAN_EID_MMIE;
1005         mmie->length = sizeof(*mmie) - 2;
1006         mmie->key_id = cpu_to_le16(key->conf.keyidx);
1007 
1008         /* PN = PN + 1 */
1009         pn64 = atomic64_inc_return(&key->conf.tx_pn);
1010 
1011         bip_ipn_set64(mmie->sequence_number, pn64);
1012 
1013         bip_aad(skb, aad);
1014 
1015         /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1016          */
1017         ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1018                                skb->data + 24, skb->len - 24, mmie->mic);
1019 
1020         return TX_CONTINUE;
1021 }
1022 
1023 ieee80211_rx_result
1024 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1025 {
1026         struct sk_buff *skb = rx->skb;
1027         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1028         struct ieee80211_key *key = rx->key;
1029         struct ieee80211_mmie *mmie;
1030         u8 aad[20], mic[8], ipn[6];
1031         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1032 
1033         if (!ieee80211_is_mgmt(hdr->frame_control))
1034                 return RX_CONTINUE;
1035 
1036         /* management frames are already linear */
1037 
1038         if (skb->len < 24 + sizeof(*mmie))
1039                 return RX_DROP_UNUSABLE;
1040 
1041         mmie = (struct ieee80211_mmie *)
1042                 (skb->data + skb->len - sizeof(*mmie));
1043         if (mmie->element_id != WLAN_EID_MMIE ||
1044             mmie->length != sizeof(*mmie) - 2)
1045                 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1046 
1047         bip_ipn_swap(ipn, mmie->sequence_number);
1048 
1049         if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1050                 key->u.aes_cmac.replays++;
1051                 return RX_DROP_UNUSABLE;
1052         }
1053 
1054         if (!(status->flag & RX_FLAG_DECRYPTED)) {
1055                 /* hardware didn't decrypt/verify MIC */
1056                 bip_aad(skb, aad);
1057                 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1058                                    skb->data + 24, skb->len - 24, mic);
1059                 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1060                         key->u.aes_cmac.icverrors++;
1061                         return RX_DROP_UNUSABLE;
1062                 }
1063         }
1064 
1065         memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1066 
1067         /* Remove MMIE */
1068         skb_trim(skb, skb->len - sizeof(*mmie));
1069 
1070         return RX_CONTINUE;
1071 }
1072 
1073 ieee80211_rx_result
1074 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1075 {
1076         struct sk_buff *skb = rx->skb;
1077         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1078         struct ieee80211_key *key = rx->key;
1079         struct ieee80211_mmie_16 *mmie;
1080         u8 aad[20], mic[16], ipn[6];
1081         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1082 
1083         if (!ieee80211_is_mgmt(hdr->frame_control))
1084                 return RX_CONTINUE;
1085 
1086         /* management frames are already linear */
1087 
1088         if (skb->len < 24 + sizeof(*mmie))
1089                 return RX_DROP_UNUSABLE;
1090 
1091         mmie = (struct ieee80211_mmie_16 *)
1092                 (skb->data + skb->len - sizeof(*mmie));
1093         if (mmie->element_id != WLAN_EID_MMIE ||
1094             mmie->length != sizeof(*mmie) - 2)
1095                 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1096 
1097         bip_ipn_swap(ipn, mmie->sequence_number);
1098 
1099         if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1100                 key->u.aes_cmac.replays++;
1101                 return RX_DROP_UNUSABLE;
1102         }
1103 
1104         if (!(status->flag & RX_FLAG_DECRYPTED)) {
1105                 /* hardware didn't decrypt/verify MIC */
1106                 bip_aad(skb, aad);
1107                 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1108                                        skb->data + 24, skb->len - 24, mic);
1109                 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1110                         key->u.aes_cmac.icverrors++;
1111                         return RX_DROP_UNUSABLE;
1112                 }
1113         }
1114 
1115         memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1116 
1117         /* Remove MMIE */
1118         skb_trim(skb, skb->len - sizeof(*mmie));
1119 
1120         return RX_CONTINUE;
1121 }
1122 
1123 ieee80211_tx_result
1124 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1125 {
1126         struct sk_buff *skb;
1127         struct ieee80211_tx_info *info;
1128         struct ieee80211_key *key = tx->key;
1129         struct ieee80211_mmie_16 *mmie;
1130         struct ieee80211_hdr *hdr;
1131         u8 aad[GMAC_AAD_LEN];
1132         u64 pn64;
1133         u8 nonce[GMAC_NONCE_LEN];
1134 
1135         if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1136                 return TX_DROP;
1137 
1138         skb = skb_peek(&tx->skbs);
1139 
1140         info = IEEE80211_SKB_CB(skb);
1141 
1142         if (info->control.hw_key)
1143                 return TX_CONTINUE;
1144 
1145         if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1146                 return TX_DROP;
1147 
1148         mmie = skb_put(skb, sizeof(*mmie));
1149         mmie->element_id = WLAN_EID_MMIE;
1150         mmie->length = sizeof(*mmie) - 2;
1151         mmie->key_id = cpu_to_le16(key->conf.keyidx);
1152 
1153         /* PN = PN + 1 */
1154         pn64 = atomic64_inc_return(&key->conf.tx_pn);
1155 
1156         bip_ipn_set64(mmie->sequence_number, pn64);
1157 
1158         bip_aad(skb, aad);
1159 
1160         hdr = (struct ieee80211_hdr *)skb->data;
1161         memcpy(nonce, hdr->addr2, ETH_ALEN);
1162         bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1163 
1164         /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1165         if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1166                                skb->data + 24, skb->len - 24, mmie->mic) < 0)
1167                 return TX_DROP;
1168 
1169         return TX_CONTINUE;
1170 }
1171 
1172 ieee80211_rx_result
1173 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1174 {
1175         struct sk_buff *skb = rx->skb;
1176         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1177         struct ieee80211_key *key = rx->key;
1178         struct ieee80211_mmie_16 *mmie;
1179         u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1180         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1181 
1182         if (!ieee80211_is_mgmt(hdr->frame_control))
1183                 return RX_CONTINUE;
1184 
1185         /* management frames are already linear */
1186 
1187         if (skb->len < 24 + sizeof(*mmie))
1188                 return RX_DROP_UNUSABLE;
1189 
1190         mmie = (struct ieee80211_mmie_16 *)
1191                 (skb->data + skb->len - sizeof(*mmie));
1192         if (mmie->element_id != WLAN_EID_MMIE ||
1193             mmie->length != sizeof(*mmie) - 2)
1194                 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1195 
1196         bip_ipn_swap(ipn, mmie->sequence_number);
1197 
1198         if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1199                 key->u.aes_gmac.replays++;
1200                 return RX_DROP_UNUSABLE;
1201         }
1202 
1203         if (!(status->flag & RX_FLAG_DECRYPTED)) {
1204                 /* hardware didn't decrypt/verify MIC */
1205                 bip_aad(skb, aad);
1206 
1207                 memcpy(nonce, hdr->addr2, ETH_ALEN);
1208                 memcpy(nonce + ETH_ALEN, ipn, 6);
1209 
1210                 mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1211                 if (!mic)
1212                         return RX_DROP_UNUSABLE;
1213                 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1214                                        skb->data + 24, skb->len - 24,
1215                                        mic) < 0 ||
1216                     crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1217                         key->u.aes_gmac.icverrors++;
1218                         kfree(mic);
1219                         return RX_DROP_UNUSABLE;
1220                 }
1221                 kfree(mic);
1222         }
1223 
1224         memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1225 
1226         /* Remove MMIE */
1227         skb_trim(skb, skb->len - sizeof(*mmie));
1228 
1229         return RX_CONTINUE;
1230 }
1231 
1232 ieee80211_tx_result
1233 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1234 {
1235         struct sk_buff *skb;
1236         struct ieee80211_tx_info *info = NULL;
1237         ieee80211_tx_result res;
1238 
1239         skb_queue_walk(&tx->skbs, skb) {
1240                 info  = IEEE80211_SKB_CB(skb);
1241 
1242                 /* handle hw-only algorithm */
1243                 if (!info->control.hw_key)
1244                         return TX_DROP;
1245 
1246                 if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1247                         res = ieee80211_crypto_cs_encrypt(tx, skb);
1248                         if (res != TX_CONTINUE)
1249                                 return res;
1250                 }
1251         }
1252 
1253         ieee80211_tx_set_protected(tx);
1254 
1255         return TX_CONTINUE;
1256 }
1257 
1258 ieee80211_rx_result
1259 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1260 {
1261         if (rx->sta && rx->sta->cipher_scheme)
1262                 return ieee80211_crypto_cs_decrypt(rx);
1263 
1264         return RX_DROP_UNUSABLE;
1265 }
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root/net/mac80211/wpa.c

DEFINITIONS
