linux/net/mac80211/wpa.c
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   1/*
   2 * Copyright 2002-2004, Instant802 Networks, Inc.
   3 * Copyright 2008, Jouni Malinen <j@w1.fi>
   4 * Copyright (C) 2016 Intel Deutschland GmbH
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10
  11#include <linux/netdevice.h>
  12#include <linux/types.h>
  13#include <linux/skbuff.h>
  14#include <linux/compiler.h>
  15#include <linux/ieee80211.h>
  16#include <linux/gfp.h>
  17#include <asm/unaligned.h>
  18#include <net/mac80211.h>
  19#include <crypto/aes.h>
  20
  21#include "ieee80211_i.h"
  22#include "michael.h"
  23#include "tkip.h"
  24#include "aes_ccm.h"
  25#include "aes_cmac.h"
  26#include "aes_gmac.h"
  27#include "aes_gcm.h"
  28#include "wpa.h"
  29
  30ieee80211_tx_result
  31ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
  32{
  33        u8 *data, *key, *mic;
  34        size_t data_len;
  35        unsigned int hdrlen;
  36        struct ieee80211_hdr *hdr;
  37        struct sk_buff *skb = tx->skb;
  38        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  39        int tail;
  40
  41        hdr = (struct ieee80211_hdr *)skb->data;
  42        if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
  43            skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
  44                return TX_CONTINUE;
  45
  46        hdrlen = ieee80211_hdrlen(hdr->frame_control);
  47        if (skb->len < hdrlen)
  48                return TX_DROP;
  49
  50        data = skb->data + hdrlen;
  51        data_len = skb->len - hdrlen;
  52
  53        if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
  54                /* Need to use software crypto for the test */
  55                info->control.hw_key = NULL;
  56        }
  57
  58        if (info->control.hw_key &&
  59            (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
  60             tx->local->ops->set_frag_threshold) &&
  61            !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
  62                /* hwaccel - with no need for SW-generated MMIC */
  63                return TX_CONTINUE;
  64        }
  65
  66        tail = MICHAEL_MIC_LEN;
  67        if (!info->control.hw_key)
  68                tail += IEEE80211_TKIP_ICV_LEN;
  69
  70        if (WARN(skb_tailroom(skb) < tail ||
  71                 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
  72                 "mmic: not enough head/tail (%d/%d,%d/%d)\n",
  73                 skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
  74                 skb_tailroom(skb), tail))
  75                return TX_DROP;
  76
  77        key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
  78        mic = skb_put(skb, MICHAEL_MIC_LEN);
  79        michael_mic(key, hdr, data, data_len, mic);
  80        if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
  81                mic[0]++;
  82
  83        return TX_CONTINUE;
  84}
  85
  86
  87ieee80211_rx_result
  88ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
  89{
  90        u8 *data, *key = NULL;
  91        size_t data_len;
  92        unsigned int hdrlen;
  93        u8 mic[MICHAEL_MIC_LEN];
  94        struct sk_buff *skb = rx->skb;
  95        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  96        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  97
  98        /*
  99         * it makes no sense to check for MIC errors on anything other
 100         * than data frames.
 101         */
 102        if (!ieee80211_is_data_present(hdr->frame_control))
 103                return RX_CONTINUE;
 104
 105        /*
 106         * No way to verify the MIC if the hardware stripped it or
 107         * the IV with the key index. In this case we have solely rely
 108         * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
 109         * MIC failure report.
 110         */
 111        if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
 112                if (status->flag & RX_FLAG_MMIC_ERROR)
 113                        goto mic_fail_no_key;
 114
 115                if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
 116                    rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
 117                        goto update_iv;
 118
 119                return RX_CONTINUE;
 120        }
 121
 122        /*
 123         * Some hardware seems to generate Michael MIC failure reports; even
 124         * though, the frame was not encrypted with TKIP and therefore has no
 125         * MIC. Ignore the flag them to avoid triggering countermeasures.
 126         */
 127        if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
 128            !(status->flag & RX_FLAG_DECRYPTED))
 129                return RX_CONTINUE;
 130
 131        if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
 132                /*
 133                 * APs with pairwise keys should never receive Michael MIC
 134                 * errors for non-zero keyidx because these are reserved for
 135                 * group keys and only the AP is sending real multicast
 136                 * frames in the BSS.
 137                 */
 138                return RX_DROP_UNUSABLE;
 139        }
 140
 141        if (status->flag & RX_FLAG_MMIC_ERROR)
 142                goto mic_fail;
 143
 144        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 145        if (skb->len < hdrlen + MICHAEL_MIC_LEN)
 146                return RX_DROP_UNUSABLE;
 147
 148        if (skb_linearize(rx->skb))
 149                return RX_DROP_UNUSABLE;
 150        hdr = (void *)skb->data;
 151
 152        data = skb->data + hdrlen;
 153        data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
 154        key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
 155        michael_mic(key, hdr, data, data_len, mic);
 156        if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
 157                goto mic_fail;
 158
 159        /* remove Michael MIC from payload */
 160        skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
 161
 162update_iv:
 163        /* update IV in key information to be able to detect replays */
 164        rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
 165        rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
 166
 167        return RX_CONTINUE;
 168
 169mic_fail:
 170        rx->key->u.tkip.mic_failures++;
 171
 172mic_fail_no_key:
 173        /*
 174         * In some cases the key can be unset - e.g. a multicast packet, in
 175         * a driver that supports HW encryption. Send up the key idx only if
 176         * the key is set.
 177         */
 178        cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
 179                                     is_multicast_ether_addr(hdr->addr1) ?
 180                                     NL80211_KEYTYPE_GROUP :
 181                                     NL80211_KEYTYPE_PAIRWISE,
 182                                     rx->key ? rx->key->conf.keyidx : -1,
 183                                     NULL, GFP_ATOMIC);
 184        return RX_DROP_UNUSABLE;
 185}
 186
 187static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 188{
 189        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 190        struct ieee80211_key *key = tx->key;
 191        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 192        unsigned int hdrlen;
 193        int len, tail;
 194        u64 pn;
 195        u8 *pos;
 196
 197        if (info->control.hw_key &&
 198            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 199            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
 200                /* hwaccel - with no need for software-generated IV */
 201                return 0;
 202        }
 203
 204        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 205        len = skb->len - hdrlen;
 206
 207        if (info->control.hw_key)
 208                tail = 0;
 209        else
 210                tail = IEEE80211_TKIP_ICV_LEN;
 211
 212        if (WARN_ON(skb_tailroom(skb) < tail ||
 213                    skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
 214                return -1;
 215
 216        pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
 217        memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
 218        pos += hdrlen;
 219
 220        /* the HW only needs room for the IV, but not the actual IV */
 221        if (info->control.hw_key &&
 222            (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 223                return 0;
 224
 225        /* Increase IV for the frame */
 226        pn = atomic64_inc_return(&key->conf.tx_pn);
 227        pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
 228
 229        /* hwaccel - with software IV */
 230        if (info->control.hw_key)
 231                return 0;
 232
 233        /* Add room for ICV */
 234        skb_put(skb, IEEE80211_TKIP_ICV_LEN);
 235
 236        return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
 237                                           key, skb, pos, len);
 238}
 239
 240
 241ieee80211_tx_result
 242ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
 243{
 244        struct sk_buff *skb;
 245
 246        ieee80211_tx_set_protected(tx);
 247
 248        skb_queue_walk(&tx->skbs, skb) {
 249                if (tkip_encrypt_skb(tx, skb) < 0)
 250                        return TX_DROP;
 251        }
 252
 253        return TX_CONTINUE;
 254}
 255
 256
 257ieee80211_rx_result
 258ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 259{
 260        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 261        int hdrlen, res, hwaccel = 0;
 262        struct ieee80211_key *key = rx->key;
 263        struct sk_buff *skb = rx->skb;
 264        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 265
 266        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 267
 268        if (!ieee80211_is_data(hdr->frame_control))
 269                return RX_CONTINUE;
 270
 271        if (!rx->sta || skb->len - hdrlen < 12)
 272                return RX_DROP_UNUSABLE;
 273
 274        /* it may be possible to optimize this a bit more */
 275        if (skb_linearize(rx->skb))
 276                return RX_DROP_UNUSABLE;
 277        hdr = (void *)skb->data;
 278
 279        /*
 280         * Let TKIP code verify IV, but skip decryption.
 281         * In the case where hardware checks the IV as well,
 282         * we don't even get here, see ieee80211_rx_h_decrypt()
 283         */
 284        if (status->flag & RX_FLAG_DECRYPTED)
 285                hwaccel = 1;
 286
 287        res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
 288                                          key, skb->data + hdrlen,
 289                                          skb->len - hdrlen, rx->sta->sta.addr,
 290                                          hdr->addr1, hwaccel, rx->security_idx,
 291                                          &rx->tkip_iv32,
 292                                          &rx->tkip_iv16);
 293        if (res != TKIP_DECRYPT_OK)
 294                return RX_DROP_UNUSABLE;
 295
 296        /* Trim ICV */
 297        skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
 298
 299        /* Remove IV */
 300        memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
 301        skb_pull(skb, IEEE80211_TKIP_IV_LEN);
 302
 303        return RX_CONTINUE;
 304}
 305
 306
 307static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
 308{
 309        __le16 mask_fc;
 310        int a4_included, mgmt;
 311        u8 qos_tid;
 312        u16 len_a;
 313        unsigned int hdrlen;
 314        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 315
 316        /*
 317         * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
 318         * Retry, PwrMgt, MoreData; set Protected
 319         */
 320        mgmt = ieee80211_is_mgmt(hdr->frame_control);
 321        mask_fc = hdr->frame_control;
 322        mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
 323                                IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
 324        if (!mgmt)
 325                mask_fc &= ~cpu_to_le16(0x0070);
 326        mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 327
 328        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 329        len_a = hdrlen - 2;
 330        a4_included = ieee80211_has_a4(hdr->frame_control);
 331
 332        if (ieee80211_is_data_qos(hdr->frame_control))
 333                qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 334        else
 335                qos_tid = 0;
 336
 337        /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
 338         * mode authentication are not allowed to collide, yet both are derived
 339         * from this vector b_0. We only set L := 1 here to indicate that the
 340         * data size can be represented in (L+1) bytes. The CCM layer will take
 341         * care of storing the data length in the top (L+1) bytes and setting
 342         * and clearing the other bits as is required to derive the two IVs.
 343         */
 344        b_0[0] = 0x1;
 345
 346        /* Nonce: Nonce Flags | A2 | PN
 347         * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
 348         */
 349        b_0[1] = qos_tid | (mgmt << 4);
 350        memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
 351        memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
 352
 353        /* AAD (extra authenticate-only data) / masked 802.11 header
 354         * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 355        put_unaligned_be16(len_a, &aad[0]);
 356        put_unaligned(mask_fc, (__le16 *)&aad[2]);
 357        memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 358
 359        /* Mask Seq#, leave Frag# */
 360        aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
 361        aad[23] = 0;
 362
 363        if (a4_included) {
 364                memcpy(&aad[24], hdr->addr4, ETH_ALEN);
 365                aad[30] = qos_tid;
 366                aad[31] = 0;
 367        } else {
 368                memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
 369                aad[24] = qos_tid;
 370        }
 371}
 372
 373
 374static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
 375{
 376        hdr[0] = pn[5];
 377        hdr[1] = pn[4];
 378        hdr[2] = 0;
 379        hdr[3] = 0x20 | (key_id << 6);
 380        hdr[4] = pn[3];
 381        hdr[5] = pn[2];
 382        hdr[6] = pn[1];
 383        hdr[7] = pn[0];
 384}
 385
 386
 387static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
 388{
 389        pn[0] = hdr[7];
 390        pn[1] = hdr[6];
 391        pn[2] = hdr[5];
 392        pn[3] = hdr[4];
 393        pn[4] = hdr[1];
 394        pn[5] = hdr[0];
 395}
 396
 397
 398static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
 399                            unsigned int mic_len)
 400{
 401        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 402        struct ieee80211_key *key = tx->key;
 403        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 404        int hdrlen, len, tail;
 405        u8 *pos;
 406        u8 pn[6];
 407        u64 pn64;
 408        u8 aad[2 * AES_BLOCK_SIZE];
 409        u8 b_0[AES_BLOCK_SIZE];
 410
 411        if (info->control.hw_key &&
 412            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 413            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 414            !((info->control.hw_key->flags &
 415               IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
 416              ieee80211_is_mgmt(hdr->frame_control))) {
 417                /*
 418                 * hwaccel has no need for preallocated room for CCMP
 419                 * header or MIC fields
 420                 */
 421                return 0;
 422        }
 423
 424        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 425        len = skb->len - hdrlen;
 426
 427        if (info->control.hw_key)
 428                tail = 0;
 429        else
 430                tail = mic_len;
 431
 432        if (WARN_ON(skb_tailroom(skb) < tail ||
 433                    skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
 434                return -1;
 435
 436        pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
 437        memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
 438
 439        /* the HW only needs room for the IV, but not the actual IV */
 440        if (info->control.hw_key &&
 441            (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 442                return 0;
 443
 444        hdr = (struct ieee80211_hdr *) pos;
 445        pos += hdrlen;
 446
 447        pn64 = atomic64_inc_return(&key->conf.tx_pn);
 448
 449        pn[5] = pn64;
 450        pn[4] = pn64 >> 8;
 451        pn[3] = pn64 >> 16;
 452        pn[2] = pn64 >> 24;
 453        pn[1] = pn64 >> 32;
 454        pn[0] = pn64 >> 40;
 455
 456        ccmp_pn2hdr(pos, pn, key->conf.keyidx);
 457
 458        /* hwaccel - with software CCMP header */
 459        if (info->control.hw_key)
 460                return 0;
 461
 462        pos += IEEE80211_CCMP_HDR_LEN;
 463        ccmp_special_blocks(skb, pn, b_0, aad);
 464        ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
 465                                  skb_put(skb, mic_len), mic_len);
 466
 467        return 0;
 468}
 469
 470
 471ieee80211_tx_result
 472ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
 473                              unsigned int mic_len)
 474{
 475        struct sk_buff *skb;
 476
 477        ieee80211_tx_set_protected(tx);
 478
 479        skb_queue_walk(&tx->skbs, skb) {
 480                if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
 481                        return TX_DROP;
 482        }
 483
 484        return TX_CONTINUE;
 485}
 486
 487
 488ieee80211_rx_result
 489ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
 490                              unsigned int mic_len)
 491{
 492        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 493        int hdrlen;
 494        struct ieee80211_key *key = rx->key;
 495        struct sk_buff *skb = rx->skb;
 496        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 497        u8 pn[IEEE80211_CCMP_PN_LEN];
 498        int data_len;
 499        int queue;
 500
 501        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 502
 503        if (!ieee80211_is_data(hdr->frame_control) &&
 504            !ieee80211_is_robust_mgmt_frame(skb))
 505                return RX_CONTINUE;
 506
 507        data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
 508        if (!rx->sta || data_len < 0)
 509                return RX_DROP_UNUSABLE;
 510
 511        if (status->flag & RX_FLAG_DECRYPTED) {
 512                if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
 513                        return RX_DROP_UNUSABLE;
 514        } else {
 515                if (skb_linearize(rx->skb))
 516                        return RX_DROP_UNUSABLE;
 517        }
 518
 519        if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
 520                ccmp_hdr2pn(pn, skb->data + hdrlen);
 521
 522                queue = rx->security_idx;
 523
 524                if (memcmp(pn, key->u.ccmp.rx_pn[queue],
 525                           IEEE80211_CCMP_PN_LEN) <= 0) {
 526                        key->u.ccmp.replays++;
 527                        return RX_DROP_UNUSABLE;
 528                }
 529
 530                if (!(status->flag & RX_FLAG_DECRYPTED)) {
 531                        u8 aad[2 * AES_BLOCK_SIZE];
 532                        u8 b_0[AES_BLOCK_SIZE];
 533                        /* hardware didn't decrypt/verify MIC */
 534                        ccmp_special_blocks(skb, pn, b_0, aad);
 535
 536                        if (ieee80211_aes_ccm_decrypt(
 537                                    key->u.ccmp.tfm, b_0, aad,
 538                                    skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
 539                                    data_len,
 540                                    skb->data + skb->len - mic_len, mic_len))
 541                                return RX_DROP_UNUSABLE;
 542                }
 543
 544                memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
 545        }
 546
 547        /* Remove CCMP header and MIC */
 548        if (pskb_trim(skb, skb->len - mic_len))
 549                return RX_DROP_UNUSABLE;
 550        memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
 551        skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
 552
 553        return RX_CONTINUE;
 554}
 555
 556static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
 557{
 558        __le16 mask_fc;
 559        u8 qos_tid;
 560        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 561
 562        memcpy(j_0, hdr->addr2, ETH_ALEN);
 563        memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
 564        j_0[13] = 0;
 565        j_0[14] = 0;
 566        j_0[AES_BLOCK_SIZE - 1] = 0x01;
 567
 568        /* AAD (extra authenticate-only data) / masked 802.11 header
 569         * FC | A1 | A2 | A3 | SC | [A4] | [QC]
 570         */
 571        put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
 572        /* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
 573         * Retry, PwrMgt, MoreData; set Protected
 574         */
 575        mask_fc = hdr->frame_control;
 576        mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
 577                                IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
 578        if (!ieee80211_is_mgmt(hdr->frame_control))
 579                mask_fc &= ~cpu_to_le16(0x0070);
 580        mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 581
 582        put_unaligned(mask_fc, (__le16 *)&aad[2]);
 583        memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 584
 585        /* Mask Seq#, leave Frag# */
 586        aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
 587        aad[23] = 0;
 588
 589        if (ieee80211_is_data_qos(hdr->frame_control))
 590                qos_tid = *ieee80211_get_qos_ctl(hdr) &
 591                        IEEE80211_QOS_CTL_TID_MASK;
 592        else
 593                qos_tid = 0;
 594
 595        if (ieee80211_has_a4(hdr->frame_control)) {
 596                memcpy(&aad[24], hdr->addr4, ETH_ALEN);
 597                aad[30] = qos_tid;
 598                aad[31] = 0;
 599        } else {
 600                memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
 601                aad[24] = qos_tid;
 602        }
 603}
 604
 605static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
 606{
 607        hdr[0] = pn[5];
 608        hdr[1] = pn[4];
 609        hdr[2] = 0;
 610        hdr[3] = 0x20 | (key_id << 6);
 611        hdr[4] = pn[3];
 612        hdr[5] = pn[2];
 613        hdr[6] = pn[1];
 614        hdr[7] = pn[0];
 615}
 616
 617static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
 618{
 619        pn[0] = hdr[7];
 620        pn[1] = hdr[6];
 621        pn[2] = hdr[5];
 622        pn[3] = hdr[4];
 623        pn[4] = hdr[1];
 624        pn[5] = hdr[0];
 625}
 626
 627static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 628{
 629        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 630        struct ieee80211_key *key = tx->key;
 631        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 632        int hdrlen, len, tail;
 633        u8 *pos;
 634        u8 pn[6];
 635        u64 pn64;
 636        u8 aad[2 * AES_BLOCK_SIZE];
 637        u8 j_0[AES_BLOCK_SIZE];
 638
 639        if (info->control.hw_key &&
 640            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
 641            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
 642            !((info->control.hw_key->flags &
 643               IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
 644              ieee80211_is_mgmt(hdr->frame_control))) {
 645                /* hwaccel has no need for preallocated room for GCMP
 646                 * header or MIC fields
 647                 */
 648                return 0;
 649        }
 650
 651        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 652        len = skb->len - hdrlen;
 653
 654        if (info->control.hw_key)
 655                tail = 0;
 656        else
 657                tail = IEEE80211_GCMP_MIC_LEN;
 658
 659        if (WARN_ON(skb_tailroom(skb) < tail ||
 660                    skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
 661                return -1;
 662
 663        pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
 664        memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
 665        skb_set_network_header(skb, skb_network_offset(skb) +
 666                                    IEEE80211_GCMP_HDR_LEN);
 667
 668        /* the HW only needs room for the IV, but not the actual IV */
 669        if (info->control.hw_key &&
 670            (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
 671                return 0;
 672
 673        hdr = (struct ieee80211_hdr *)pos;
 674        pos += hdrlen;
 675
 676        pn64 = atomic64_inc_return(&key->conf.tx_pn);
 677
 678        pn[5] = pn64;
 679        pn[4] = pn64 >> 8;
 680        pn[3] = pn64 >> 16;
 681        pn[2] = pn64 >> 24;
 682        pn[1] = pn64 >> 32;
 683        pn[0] = pn64 >> 40;
 684
 685        gcmp_pn2hdr(pos, pn, key->conf.keyidx);
 686
 687        /* hwaccel - with software GCMP header */
 688        if (info->control.hw_key)
 689                return 0;
 690
 691        pos += IEEE80211_GCMP_HDR_LEN;
 692        gcmp_special_blocks(skb, pn, j_0, aad);
 693        ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
 694                                  skb_put(skb, IEEE80211_GCMP_MIC_LEN));
 695
 696        return 0;
 697}
 698
 699ieee80211_tx_result
 700ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
 701{
 702        struct sk_buff *skb;
 703
 704        ieee80211_tx_set_protected(tx);
 705
 706        skb_queue_walk(&tx->skbs, skb) {
 707                if (gcmp_encrypt_skb(tx, skb) < 0)
 708                        return TX_DROP;
 709        }
 710
 711        return TX_CONTINUE;
 712}
 713
 714ieee80211_rx_result
 715ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
 716{
 717        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 718        int hdrlen;
 719        struct ieee80211_key *key = rx->key;
 720        struct sk_buff *skb = rx->skb;
 721        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 722        u8 pn[IEEE80211_GCMP_PN_LEN];
 723        int data_len;
 724        int queue;
 725
 726        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 727
 728        if (!ieee80211_is_data(hdr->frame_control) &&
 729            !ieee80211_is_robust_mgmt_frame(skb))
 730                return RX_CONTINUE;
 731
 732        data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN -
 733                   IEEE80211_GCMP_MIC_LEN;
 734        if (!rx->sta || data_len < 0)
 735                return RX_DROP_UNUSABLE;
 736
 737        if (status->flag & RX_FLAG_DECRYPTED) {
 738                if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
 739                        return RX_DROP_UNUSABLE;
 740        } else {
 741                if (skb_linearize(rx->skb))
 742                        return RX_DROP_UNUSABLE;
 743        }
 744
 745        if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
 746                gcmp_hdr2pn(pn, skb->data + hdrlen);
 747
 748                queue = rx->security_idx;
 749
 750                if (memcmp(pn, key->u.gcmp.rx_pn[queue],
 751                           IEEE80211_GCMP_PN_LEN) <= 0) {
 752                        key->u.gcmp.replays++;
 753                        return RX_DROP_UNUSABLE;
 754                }
 755
 756                if (!(status->flag & RX_FLAG_DECRYPTED)) {
 757                        u8 aad[2 * AES_BLOCK_SIZE];
 758                        u8 j_0[AES_BLOCK_SIZE];
 759                        /* hardware didn't decrypt/verify MIC */
 760                        gcmp_special_blocks(skb, pn, j_0, aad);
 761
 762                        if (ieee80211_aes_gcm_decrypt(
 763                                    key->u.gcmp.tfm, j_0, aad,
 764                                    skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
 765                                    data_len,
 766                                    skb->data + skb->len -
 767                                    IEEE80211_GCMP_MIC_LEN))
 768                                return RX_DROP_UNUSABLE;
 769                }
 770
 771                memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
 772        }
 773
 774        /* Remove GCMP header and MIC */
 775        if (pskb_trim(skb, skb->len - IEEE80211_GCMP_MIC_LEN))
 776                return RX_DROP_UNUSABLE;
 777        memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
 778        skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
 779
 780        return RX_CONTINUE;
 781}
 782
 783static ieee80211_tx_result
 784ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
 785                            struct sk_buff *skb)
 786{
 787        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 788        struct ieee80211_key *key = tx->key;
 789        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 790        int hdrlen;
 791        u8 *pos, iv_len = key->conf.iv_len;
 792
 793        if (info->control.hw_key &&
 794            !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
 795                /* hwaccel has no need for preallocated head room */
 796                return TX_CONTINUE;
 797        }
 798
 799        if (unlikely(skb_headroom(skb) < iv_len &&
 800                     pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
 801                return TX_DROP;
 802
 803        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 804
 805        pos = skb_push(skb, iv_len);
 806        memmove(pos, pos + iv_len, hdrlen);
 807
 808        return TX_CONTINUE;
 809}
 810
 811static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
 812{
 813        int i;
 814
 815        /* pn is little endian */
 816        for (i = len - 1; i >= 0; i--) {
 817                if (pn1[i] < pn2[i])
 818                        return -1;
 819                else if (pn1[i] > pn2[i])
 820                        return 1;
 821        }
 822
 823        return 0;
 824}
 825
 826static ieee80211_rx_result
 827ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
 828{
 829        struct ieee80211_key *key = rx->key;
 830        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 831        const struct ieee80211_cipher_scheme *cs = NULL;
 832        int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 833        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 834        int data_len;
 835        u8 *rx_pn;
 836        u8 *skb_pn;
 837        u8 qos_tid;
 838
 839        if (!rx->sta || !rx->sta->cipher_scheme ||
 840            !(status->flag & RX_FLAG_DECRYPTED))
 841                return RX_DROP_UNUSABLE;
 842
 843        if (!ieee80211_is_data(hdr->frame_control))
 844                return RX_CONTINUE;
 845
 846        cs = rx->sta->cipher_scheme;
 847
 848        data_len = rx->skb->len - hdrlen - cs->hdr_len;
 849
 850        if (data_len < 0)
 851                return RX_DROP_UNUSABLE;
 852
 853        if (ieee80211_is_data_qos(hdr->frame_control))
 854                qos_tid = *ieee80211_get_qos_ctl(hdr) &
 855                                IEEE80211_QOS_CTL_TID_MASK;
 856        else
 857                qos_tid = 0;
 858
 859        if (skb_linearize(rx->skb))
 860                return RX_DROP_UNUSABLE;
 861
 862        hdr = (struct ieee80211_hdr *)rx->skb->data;
 863
 864        rx_pn = key->u.gen.rx_pn[qos_tid];
 865        skb_pn = rx->skb->data + hdrlen + cs->pn_off;
 866
 867        if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
 868                return RX_DROP_UNUSABLE;
 869
 870        memcpy(rx_pn, skb_pn, cs->pn_len);
 871
 872        /* remove security header and MIC */
 873        if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
 874                return RX_DROP_UNUSABLE;
 875
 876        memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
 877        skb_pull(rx->skb, cs->hdr_len);
 878
 879        return RX_CONTINUE;
 880}
 881
 882static void bip_aad(struct sk_buff *skb, u8 *aad)
 883{
 884        __le16 mask_fc;
 885        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 886
 887        /* BIP AAD: FC(masked) || A1 || A2 || A3 */
 888
 889        /* FC type/subtype */
 890        /* Mask FC Retry, PwrMgt, MoreData flags to zero */
 891        mask_fc = hdr->frame_control;
 892        mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
 893                                IEEE80211_FCTL_MOREDATA);
 894        put_unaligned(mask_fc, (__le16 *) &aad[0]);
 895        /* A1 || A2 || A3 */
 896        memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
 897}
 898
 899
 900static inline void bip_ipn_set64(u8 *d, u64 pn)
 901{
 902        *d++ = pn;
 903        *d++ = pn >> 8;
 904        *d++ = pn >> 16;
 905        *d++ = pn >> 24;
 906        *d++ = pn >> 32;
 907        *d = pn >> 40;
 908}
 909
 910static inline void bip_ipn_swap(u8 *d, const u8 *s)
 911{
 912        *d++ = s[5];
 913        *d++ = s[4];
 914        *d++ = s[3];
 915        *d++ = s[2];
 916        *d++ = s[1];
 917        *d = s[0];
 918}
 919
 920
 921ieee80211_tx_result
 922ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
 923{
 924        struct sk_buff *skb;
 925        struct ieee80211_tx_info *info;
 926        struct ieee80211_key *key = tx->key;
 927        struct ieee80211_mmie *mmie;
 928        u8 aad[20];
 929        u64 pn64;
 930
 931        if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
 932                return TX_DROP;
 933
 934        skb = skb_peek(&tx->skbs);
 935
 936        info = IEEE80211_SKB_CB(skb);
 937
 938        if (info->control.hw_key)
 939                return TX_CONTINUE;
 940
 941        if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
 942                return TX_DROP;
 943
 944        mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
 945        mmie->element_id = WLAN_EID_MMIE;
 946        mmie->length = sizeof(*mmie) - 2;
 947        mmie->key_id = cpu_to_le16(key->conf.keyidx);
 948
 949        /* PN = PN + 1 */
 950        pn64 = atomic64_inc_return(&key->conf.tx_pn);
 951
 952        bip_ipn_set64(mmie->sequence_number, pn64);
 953
 954        bip_aad(skb, aad);
 955
 956        /*
 957         * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
 958         */
 959        ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
 960                           skb->data + 24, skb->len - 24, mmie->mic);
 961
 962        return TX_CONTINUE;
 963}
 964
 965ieee80211_tx_result
 966ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
 967{
 968        struct sk_buff *skb;
 969        struct ieee80211_tx_info *info;
 970        struct ieee80211_key *key = tx->key;
 971        struct ieee80211_mmie_16 *mmie;
 972        u8 aad[20];
 973        u64 pn64;
 974
 975        if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
 976                return TX_DROP;
 977
 978        skb = skb_peek(&tx->skbs);
 979
 980        info = IEEE80211_SKB_CB(skb);
 981
 982        if (info->control.hw_key)
 983                return TX_CONTINUE;
 984
 985        if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
 986                return TX_DROP;
 987
 988        mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
 989        mmie->element_id = WLAN_EID_MMIE;
 990        mmie->length = sizeof(*mmie) - 2;
 991        mmie->key_id = cpu_to_le16(key->conf.keyidx);
 992
 993        /* PN = PN + 1 */
 994        pn64 = atomic64_inc_return(&key->conf.tx_pn);
 995
 996        bip_ipn_set64(mmie->sequence_number, pn64);
 997
 998        bip_aad(skb, aad);
 999
1000        /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1001         */
1002        ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1003                               skb->data + 24, skb->len - 24, mmie->mic);
1004
1005        return TX_CONTINUE;
1006}
1007
1008ieee80211_rx_result
1009ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1010{
1011        struct sk_buff *skb = rx->skb;
1012        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1013        struct ieee80211_key *key = rx->key;
1014        struct ieee80211_mmie *mmie;
1015        u8 aad[20], mic[8], ipn[6];
1016        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1017
1018        if (!ieee80211_is_mgmt(hdr->frame_control))
1019                return RX_CONTINUE;
1020
1021        /* management frames are already linear */
1022
1023        if (skb->len < 24 + sizeof(*mmie))
1024                return RX_DROP_UNUSABLE;
1025
1026        mmie = (struct ieee80211_mmie *)
1027                (skb->data + skb->len - sizeof(*mmie));
1028        if (mmie->element_id != WLAN_EID_MMIE ||
1029            mmie->length != sizeof(*mmie) - 2)
1030                return RX_DROP_UNUSABLE; /* Invalid MMIE */
1031
1032        bip_ipn_swap(ipn, mmie->sequence_number);
1033
1034        if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1035                key->u.aes_cmac.replays++;
1036                return RX_DROP_UNUSABLE;
1037        }
1038
1039        if (!(status->flag & RX_FLAG_DECRYPTED)) {
1040                /* hardware didn't decrypt/verify MIC */
1041                bip_aad(skb, aad);
1042                ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1043                                   skb->data + 24, skb->len - 24, mic);
1044                if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1045                        key->u.aes_cmac.icverrors++;
1046                        return RX_DROP_UNUSABLE;
1047                }
1048        }
1049
1050        memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1051
1052        /* Remove MMIE */
1053        skb_trim(skb, skb->len - sizeof(*mmie));
1054
1055        return RX_CONTINUE;
1056}
1057
1058ieee80211_rx_result
1059ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1060{
1061        struct sk_buff *skb = rx->skb;
1062        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1063        struct ieee80211_key *key = rx->key;
1064        struct ieee80211_mmie_16 *mmie;
1065        u8 aad[20], mic[16], ipn[6];
1066        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1067
1068        if (!ieee80211_is_mgmt(hdr->frame_control))
1069                return RX_CONTINUE;
1070
1071        /* management frames are already linear */
1072
1073        if (skb->len < 24 + sizeof(*mmie))
1074                return RX_DROP_UNUSABLE;
1075
1076        mmie = (struct ieee80211_mmie_16 *)
1077                (skb->data + skb->len - sizeof(*mmie));
1078        if (mmie->element_id != WLAN_EID_MMIE ||
1079            mmie->length != sizeof(*mmie) - 2)
1080                return RX_DROP_UNUSABLE; /* Invalid MMIE */
1081
1082        bip_ipn_swap(ipn, mmie->sequence_number);
1083
1084        if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1085                key->u.aes_cmac.replays++;
1086                return RX_DROP_UNUSABLE;
1087        }
1088
1089        if (!(status->flag & RX_FLAG_DECRYPTED)) {
1090                /* hardware didn't decrypt/verify MIC */
1091                bip_aad(skb, aad);
1092                ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1093                                       skb->data + 24, skb->len - 24, mic);
1094                if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1095                        key->u.aes_cmac.icverrors++;
1096                        return RX_DROP_UNUSABLE;
1097                }
1098        }
1099
1100        memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1101
1102        /* Remove MMIE */
1103        skb_trim(skb, skb->len - sizeof(*mmie));
1104
1105        return RX_CONTINUE;
1106}
1107
1108ieee80211_tx_result
1109ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1110{
1111        struct sk_buff *skb;
1112        struct ieee80211_tx_info *info;
1113        struct ieee80211_key *key = tx->key;
1114        struct ieee80211_mmie_16 *mmie;
1115        struct ieee80211_hdr *hdr;
1116        u8 aad[20];
1117        u64 pn64;
1118        u8 nonce[12];
1119
1120        if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1121                return TX_DROP;
1122
1123        skb = skb_peek(&tx->skbs);
1124
1125        info = IEEE80211_SKB_CB(skb);
1126
1127        if (info->control.hw_key)
1128                return TX_CONTINUE;
1129
1130        if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1131                return TX_DROP;
1132
1133        mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
1134        mmie->element_id = WLAN_EID_MMIE;
1135        mmie->length = sizeof(*mmie) - 2;
1136        mmie->key_id = cpu_to_le16(key->conf.keyidx);
1137
1138        /* PN = PN + 1 */
1139        pn64 = atomic64_inc_return(&key->conf.tx_pn);
1140
1141        bip_ipn_set64(mmie->sequence_number, pn64);
1142
1143        bip_aad(skb, aad);
1144
1145        hdr = (struct ieee80211_hdr *)skb->data;
1146        memcpy(nonce, hdr->addr2, ETH_ALEN);
1147        bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1148
1149        /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1150        if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1151                               skb->data + 24, skb->len - 24, mmie->mic) < 0)
1152                return TX_DROP;
1153
1154        return TX_CONTINUE;
1155}
1156
1157ieee80211_rx_result
1158ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1159{
1160        struct sk_buff *skb = rx->skb;
1161        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1162        struct ieee80211_key *key = rx->key;
1163        struct ieee80211_mmie_16 *mmie;
1164        u8 aad[20], mic[16], ipn[6], nonce[12];
1165        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1166
1167        if (!ieee80211_is_mgmt(hdr->frame_control))
1168                return RX_CONTINUE;
1169
1170        /* management frames are already linear */
1171
1172        if (skb->len < 24 + sizeof(*mmie))
1173                return RX_DROP_UNUSABLE;
1174
1175        mmie = (struct ieee80211_mmie_16 *)
1176                (skb->data + skb->len - sizeof(*mmie));
1177        if (mmie->element_id != WLAN_EID_MMIE ||
1178            mmie->length != sizeof(*mmie) - 2)
1179                return RX_DROP_UNUSABLE; /* Invalid MMIE */
1180
1181        bip_ipn_swap(ipn, mmie->sequence_number);
1182
1183        if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1184                key->u.aes_gmac.replays++;
1185                return RX_DROP_UNUSABLE;
1186        }
1187
1188        if (!(status->flag & RX_FLAG_DECRYPTED)) {
1189                /* hardware didn't decrypt/verify MIC */
1190                bip_aad(skb, aad);
1191
1192                memcpy(nonce, hdr->addr2, ETH_ALEN);
1193                memcpy(nonce + ETH_ALEN, ipn, 6);
1194
1195                if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1196                                       skb->data + 24, skb->len - 24,
1197                                       mic) < 0 ||
1198                    memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
1199                        key->u.aes_gmac.icverrors++;
1200                        return RX_DROP_UNUSABLE;
1201                }
1202        }
1203
1204        memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1205
1206        /* Remove MMIE */
1207        skb_trim(skb, skb->len - sizeof(*mmie));
1208
1209        return RX_CONTINUE;
1210}
1211
1212ieee80211_tx_result
1213ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1214{
1215        struct sk_buff *skb;
1216        struct ieee80211_tx_info *info = NULL;
1217        ieee80211_tx_result res;
1218
1219        skb_queue_walk(&tx->skbs, skb) {
1220                info  = IEEE80211_SKB_CB(skb);
1221
1222                /* handle hw-only algorithm */
1223                if (!info->control.hw_key)
1224                        return TX_DROP;
1225
1226                if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1227                        res = ieee80211_crypto_cs_encrypt(tx, skb);
1228                        if (res != TX_CONTINUE)
1229                                return res;
1230                }
1231        }
1232
1233        ieee80211_tx_set_protected(tx);
1234
1235        return TX_CONTINUE;
1236}
1237
1238ieee80211_rx_result
1239ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1240{
1241        if (rx->sta && rx->sta->cipher_scheme)
1242                return ieee80211_crypto_cs_decrypt(rx);
1243
1244        return RX_DROP_UNUSABLE;
1245}
1246