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 * Copyright (C) 2020-2023 Intel Corporation 7 */ 8 9 #include <linux/netdevice.h> 10 #include <linux/types.h> 11 #include <linux/skbuff.h> 12 #include <linux/compiler.h> 13 #include <linux/ieee80211.h> 14 #include <linux/gfp.h> 15 #include <linux/unaligned.h> 16 #include <net/mac80211.h> 17 #include <crypto/aes.h> 18 #include <crypto/utils.h> 19 20 #include "ieee80211_i.h" 21 #include "michael.h" 22 #include "tkip.h" 23 #include "aes_ccm.h" 24 #include "aes_cmac.h" 25 #include "aes_gmac.h" 26 #include "aes_gcm.h" 27 #include "wpa.h" 28 29 ieee80211_tx_result 30 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) 31 { 32 u8 *data, *key, *mic; 33 size_t data_len; 34 unsigned int hdrlen; 35 struct ieee80211_hdr *hdr; 36 struct sk_buff *skb = tx->skb; 37 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 38 int tail; 39 40 hdr = (struct ieee80211_hdr *)skb->data; 41 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 42 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control)) 43 return TX_CONTINUE; 44 45 hdrlen = ieee80211_hdrlen(hdr->frame_control); 46 if (skb->len < hdrlen) 47 return TX_DROP; 48 49 data = skb->data + hdrlen; 50 data_len = skb->len - hdrlen; 51 52 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { 53 /* Need to use software crypto for the test */ 54 info->control.hw_key = NULL; 55 } 56 57 if (info->control.hw_key && 58 (info->flags & IEEE80211_TX_CTL_DONTFRAG || 59 ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) && 60 !(tx->key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC | 61 IEEE80211_KEY_FLAG_PUT_MIC_SPACE))) { 62 /* hwaccel - with no need for SW-generated MMIC or MIC space */ 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 mic = skb_put(skb, MICHAEL_MIC_LEN); 78 79 if (tx->key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) { 80 /* Zeroed MIC can help with debug */ 81 memset(mic, 0, MICHAEL_MIC_LEN); 82 return TX_CONTINUE; 83 } 84 85 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; 86 michael_mic(key, hdr, data, data_len, mic); 87 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) 88 mic[0]++; 89 90 return TX_CONTINUE; 91 } 92 93 94 ieee80211_rx_result 95 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) 96 { 97 u8 *data, *key = NULL; 98 size_t data_len; 99 unsigned int hdrlen; 100 u8 mic[MICHAEL_MIC_LEN]; 101 struct sk_buff *skb = rx->skb; 102 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 103 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 104 105 /* 106 * it makes no sense to check for MIC errors on anything other 107 * than data frames. 108 */ 109 if (!ieee80211_is_data_present(hdr->frame_control)) 110 return RX_CONTINUE; 111 112 /* 113 * No way to verify the MIC if the hardware stripped it or 114 * the IV with the key index. In this case we have solely rely 115 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a 116 * MIC failure report. 117 */ 118 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { 119 if (status->flag & RX_FLAG_MMIC_ERROR) 120 goto mic_fail_no_key; 121 122 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key && 123 rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP) 124 goto update_iv; 125 126 return RX_CONTINUE; 127 } 128 129 /* 130 * Some hardware seems to generate Michael MIC failure reports; even 131 * though, the frame was not encrypted with TKIP and therefore has no 132 * MIC. Ignore the flag them to avoid triggering countermeasures. 133 */ 134 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || 135 !(status->flag & RX_FLAG_DECRYPTED)) 136 return RX_CONTINUE; 137 138 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) { 139 /* 140 * APs with pairwise keys should never receive Michael MIC 141 * errors for non-zero keyidx because these are reserved for 142 * group keys and only the AP is sending real multicast 143 * frames in the BSS. 144 */ 145 return RX_DROP_U_AP_RX_GROUPCAST; 146 } 147 148 if (status->flag & RX_FLAG_MMIC_ERROR) 149 goto mic_fail; 150 151 hdrlen = ieee80211_hdrlen(hdr->frame_control); 152 if (skb->len < hdrlen + MICHAEL_MIC_LEN) 153 return RX_DROP_U_SHORT_MMIC; 154 155 if (skb_linearize(rx->skb)) 156 return RX_DROP_U_OOM; 157 hdr = (void *)skb->data; 158 159 data = skb->data + hdrlen; 160 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; 161 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]; 162 michael_mic(key, hdr, data, data_len, mic); 163 if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN)) 164 goto mic_fail; 165 166 /* remove Michael MIC from payload */ 167 skb_trim(skb, skb->len - MICHAEL_MIC_LEN); 168 169 update_iv: 170 /* update IV in key information to be able to detect replays */ 171 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip.iv32; 172 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip.iv16; 173 174 return RX_CONTINUE; 175 176 mic_fail: 177 rx->key->u.tkip.mic_failures++; 178 179 mic_fail_no_key: 180 /* 181 * In some cases the key can be unset - e.g. a multicast packet, in 182 * a driver that supports HW encryption. Send up the key idx only if 183 * the key is set. 184 */ 185 cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2, 186 is_multicast_ether_addr(hdr->addr1) ? 187 NL80211_KEYTYPE_GROUP : 188 NL80211_KEYTYPE_PAIRWISE, 189 rx->key ? rx->key->conf.keyidx : -1, 190 NULL, GFP_ATOMIC); 191 return RX_DROP_U_MMIC_FAIL; 192 } 193 194 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 195 { 196 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 197 struct ieee80211_key *key = tx->key; 198 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 199 unsigned int hdrlen; 200 int len, tail; 201 u64 pn; 202 u8 *pos; 203 204 if (info->control.hw_key && 205 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 206 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) { 207 /* hwaccel - with no need for software-generated IV */ 208 return 0; 209 } 210 211 hdrlen = ieee80211_hdrlen(hdr->frame_control); 212 len = skb->len - hdrlen; 213 214 if (info->control.hw_key) 215 tail = 0; 216 else 217 tail = IEEE80211_TKIP_ICV_LEN; 218 219 if (WARN_ON(skb_tailroom(skb) < tail || 220 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN)) 221 return -1; 222 223 pos = skb_push(skb, IEEE80211_TKIP_IV_LEN); 224 memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen); 225 pos += hdrlen; 226 227 /* the HW only needs room for the IV, but not the actual IV */ 228 if (info->control.hw_key && 229 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) 230 return 0; 231 232 /* Increase IV for the frame */ 233 pn = atomic64_inc_return(&key->conf.tx_pn); 234 pos = ieee80211_tkip_add_iv(pos, &key->conf, pn); 235 236 /* hwaccel - with software IV */ 237 if (info->control.hw_key) 238 return 0; 239 240 /* Add room for ICV */ 241 skb_put(skb, IEEE80211_TKIP_ICV_LEN); 242 243 return ieee80211_tkip_encrypt_data(&tx->local->wep_tx_ctx, 244 key, skb, pos, len); 245 } 246 247 248 ieee80211_tx_result 249 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) 250 { 251 struct sk_buff *skb; 252 253 ieee80211_tx_set_protected(tx); 254 255 skb_queue_walk(&tx->skbs, skb) { 256 if (tkip_encrypt_skb(tx, skb) < 0) 257 return TX_DROP; 258 } 259 260 return TX_CONTINUE; 261 } 262 263 264 ieee80211_rx_result 265 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 266 { 267 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; 268 int hdrlen, res, hwaccel = 0; 269 struct ieee80211_key *key = rx->key; 270 struct sk_buff *skb = rx->skb; 271 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 272 273 hdrlen = ieee80211_hdrlen(hdr->frame_control); 274 275 if (!ieee80211_is_data(hdr->frame_control)) 276 return RX_CONTINUE; 277 278 if (!rx->sta || skb->len - hdrlen < 12) 279 return RX_DROP_U_SHORT_TKIP; 280 281 /* it may be possible to optimize this a bit more */ 282 if (skb_linearize(rx->skb)) 283 return RX_DROP_U_OOM; 284 hdr = (void *)skb->data; 285 286 /* 287 * Let TKIP code verify IV, but skip decryption. 288 * In the case where hardware checks the IV as well, 289 * we don't even get here, see ieee80211_rx_h_decrypt() 290 */ 291 if (status->flag & RX_FLAG_DECRYPTED) 292 hwaccel = 1; 293 294 res = ieee80211_tkip_decrypt_data(&rx->local->wep_rx_ctx, 295 key, skb->data + hdrlen, 296 skb->len - hdrlen, rx->sta->sta.addr, 297 hdr->addr1, hwaccel, rx->security_idx, 298 &rx->tkip.iv32, 299 &rx->tkip.iv16); 300 if (res != TKIP_DECRYPT_OK) 301 return RX_DROP_U_TKIP_FAIL; 302 303 /* Trim ICV */ 304 if (!(status->flag & RX_FLAG_ICV_STRIPPED)) 305 skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN); 306 307 /* Remove IV */ 308 memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen); 309 skb_pull(skb, IEEE80211_TKIP_IV_LEN); 310 311 return RX_CONTINUE; 312 } 313 314 /* 315 * Calculate AAD for CCMP/GCMP, returning qos_tid since we 316 * need that in CCMP also for b_0. 317 */ 318 static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu, 319 bool aad_nonce_computed) 320 { 321 struct ieee80211_hdr *hdr = (void *)skb->data; 322 __le16 mask_fc; 323 int a4_included, mgmt; 324 u8 qos_tid; 325 u16 len_a = 22; 326 327 /* 328 * Mask FC: zero subtype b4 b5 b6 (if not mgmt) 329 * Retry, PwrMgt, MoreData, Order (if Qos Data); set Protected 330 */ 331 mgmt = ieee80211_is_mgmt(hdr->frame_control); 332 mask_fc = hdr->frame_control; 333 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | 334 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); 335 if (!mgmt) 336 mask_fc &= ~cpu_to_le16(0x0070); 337 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 338 339 a4_included = ieee80211_has_a4(hdr->frame_control); 340 if (a4_included) 341 len_a += 6; 342 343 if (ieee80211_is_data_qos(hdr->frame_control)) { 344 qos_tid = *ieee80211_get_qos_ctl(hdr); 345 346 if (spp_amsdu) 347 qos_tid &= IEEE80211_QOS_CTL_TID_MASK | 348 IEEE80211_QOS_CTL_A_MSDU_PRESENT; 349 else 350 qos_tid &= IEEE80211_QOS_CTL_TID_MASK; 351 352 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_ORDER); 353 len_a += 2; 354 } else { 355 qos_tid = 0; 356 } 357 358 /* AAD (extra authenticate-only data) / masked 802.11 header 359 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 360 put_unaligned_be16(len_a, &aad[0]); 361 put_unaligned(mask_fc, (__le16 *)&aad[2]); 362 if (!aad_nonce_computed) 363 memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN); 364 365 /* Mask Seq#, leave Frag# */ 366 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 367 aad[23] = 0; 368 369 if (a4_included) { 370 memcpy(&aad[24], hdr->addr4, ETH_ALEN); 371 aad[30] = qos_tid; 372 aad[31] = 0; 373 } else { 374 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); 375 aad[24] = qos_tid; 376 } 377 378 return qos_tid; 379 } 380 381 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad, 382 bool spp_amsdu, bool aad_nonce_computed) 383 { 384 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 385 u8 qos_tid = ccmp_gcmp_aad(skb, aad, spp_amsdu, aad_nonce_computed); 386 387 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC 388 * mode authentication are not allowed to collide, yet both are derived 389 * from this vector b_0. We only set L := 1 here to indicate that the 390 * data size can be represented in (L+1) bytes. The CCM layer will take 391 * care of storing the data length in the top (L+1) bytes and setting 392 * and clearing the other bits as is required to derive the two IVs. 393 */ 394 b_0[0] = 0x1; 395 396 /* Nonce: Nonce Flags | A2 | PN 397 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) 398 */ 399 b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4); 400 if (!aad_nonce_computed) 401 memcpy(&b_0[2], hdr->addr2, ETH_ALEN); 402 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN); 403 } 404 405 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 406 { 407 hdr[0] = pn[5]; 408 hdr[1] = pn[4]; 409 hdr[2] = 0; 410 hdr[3] = 0x20 | (key_id << 6); 411 hdr[4] = pn[3]; 412 hdr[5] = pn[2]; 413 hdr[6] = pn[1]; 414 hdr[7] = pn[0]; 415 } 416 417 418 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) 419 { 420 pn[0] = hdr[7]; 421 pn[1] = hdr[6]; 422 pn[2] = hdr[5]; 423 pn[3] = hdr[4]; 424 pn[4] = hdr[1]; 425 pn[5] = hdr[0]; 426 } 427 428 429 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb, 430 unsigned int mic_len) 431 { 432 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 433 struct ieee80211_key *key = tx->key; 434 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 435 int hdrlen, len, tail; 436 u8 *pos; 437 u8 pn[6]; 438 u64 pn64; 439 u8 aad[CCM_AAD_LEN]; 440 u8 b_0[AES_BLOCK_SIZE]; 441 442 if (info->control.hw_key && 443 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 444 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && 445 !((info->control.hw_key->flags & 446 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && 447 ieee80211_is_mgmt(hdr->frame_control))) { 448 /* 449 * hwaccel has no need for preallocated room for CCMP 450 * header or MIC fields 451 */ 452 return 0; 453 } 454 455 hdrlen = ieee80211_hdrlen(hdr->frame_control); 456 len = skb->len - hdrlen; 457 458 if (info->control.hw_key) 459 tail = 0; 460 else 461 tail = mic_len; 462 463 if (WARN_ON(skb_tailroom(skb) < tail || 464 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN)) 465 return -1; 466 467 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN); 468 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen); 469 470 /* the HW only needs room for the IV, but not the actual IV */ 471 if (info->control.hw_key && 472 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) 473 return 0; 474 475 pos += hdrlen; 476 477 pn64 = atomic64_inc_return(&key->conf.tx_pn); 478 479 pn[5] = pn64; 480 pn[4] = pn64 >> 8; 481 pn[3] = pn64 >> 16; 482 pn[2] = pn64 >> 24; 483 pn[1] = pn64 >> 32; 484 pn[0] = pn64 >> 40; 485 486 ccmp_pn2hdr(pos, pn, key->conf.keyidx); 487 488 /* hwaccel - with software CCMP header */ 489 if (info->control.hw_key) 490 return 0; 491 492 pos += IEEE80211_CCMP_HDR_LEN; 493 ccmp_special_blocks(skb, pn, b_0, aad, 494 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU, 495 false); 496 return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len, 497 skb_put(skb, mic_len)); 498 } 499 500 501 ieee80211_tx_result 502 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx, 503 unsigned int mic_len) 504 { 505 struct sk_buff *skb; 506 507 ieee80211_tx_set_protected(tx); 508 509 skb_queue_walk(&tx->skbs, skb) { 510 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0) 511 return TX_DROP; 512 } 513 514 return TX_CONTINUE; 515 } 516 517 518 ieee80211_rx_result 519 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx, 520 unsigned int mic_len) 521 { 522 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 523 int hdrlen; 524 struct ieee80211_key *key = rx->key; 525 struct sk_buff *skb = rx->skb; 526 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 527 u8 pn[IEEE80211_CCMP_PN_LEN]; 528 int data_len; 529 int queue; 530 531 hdrlen = ieee80211_hdrlen(hdr->frame_control); 532 533 if (!ieee80211_is_data(hdr->frame_control) && 534 !ieee80211_is_robust_mgmt_frame(skb) && 535 !ieee80211_require_encrypted_assoc(hdr->frame_control, rx->sta)) 536 return RX_CONTINUE; 537 538 if (status->flag & RX_FLAG_DECRYPTED) { 539 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN)) 540 return RX_DROP_U_SHORT_CCMP; 541 if (status->flag & RX_FLAG_MIC_STRIPPED) 542 mic_len = 0; 543 } else { 544 if (skb_linearize(rx->skb)) 545 return RX_DROP_U_OOM; 546 } 547 548 /* reload hdr - skb might have been reallocated */ 549 hdr = (void *)rx->skb->data; 550 551 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len; 552 if (!rx->sta || data_len < 0) 553 return RX_DROP_U_SHORT_CCMP; 554 555 if (!(status->flag & RX_FLAG_PN_VALIDATED)) { 556 int res; 557 558 ccmp_hdr2pn(pn, skb->data + hdrlen); 559 560 queue = rx->security_idx; 561 562 res = memcmp(pn, key->u.ccmp.rx_pn[queue], 563 IEEE80211_CCMP_PN_LEN); 564 if (res < 0 || 565 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) { 566 key->u.ccmp.replays++; 567 return RX_DROP_U_REPLAY; 568 } 569 570 if (!(status->flag & RX_FLAG_DECRYPTED)) { 571 u8 aad[2 * AES_BLOCK_SIZE]; 572 u8 b_0[AES_BLOCK_SIZE]; 573 bool aad_nonce_computed = false; 574 575 if (is_unicast_ether_addr(hdr->addr1) && 576 !ieee80211_is_data(hdr->frame_control)) { 577 /* AAD computation */ 578 memcpy(&aad[4], rx->link_addrs, 3 * ETH_ALEN); 579 /* Nonce computation */ 580 ether_addr_copy(&b_0[2], 581 &rx->link_addrs[ETH_ALEN]); 582 aad_nonce_computed = true; 583 } 584 585 /* hardware didn't decrypt/verify MIC */ 586 ccmp_special_blocks(skb, pn, b_0, aad, 587 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU, 588 aad_nonce_computed); 589 590 if (ieee80211_aes_ccm_decrypt( 591 key->u.ccmp.tfm, b_0, aad, 592 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN, 593 data_len, 594 skb->data + skb->len - mic_len)) 595 return RX_DROP_U_MIC_FAIL; 596 } 597 598 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN); 599 if (unlikely(ieee80211_is_frag(hdr))) 600 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN); 601 } 602 603 /* Remove CCMP header and MIC */ 604 if (pskb_trim(skb, skb->len - mic_len)) 605 return RX_DROP_U_SHORT_CCMP_MIC; 606 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen); 607 skb_pull(skb, IEEE80211_CCMP_HDR_LEN); 608 609 return RX_CONTINUE; 610 } 611 612 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad, 613 bool spp_amsdu, bool aad_nonce_computed) 614 { 615 struct ieee80211_hdr *hdr = (void *)skb->data; 616 617 if (!aad_nonce_computed) 618 memcpy(j_0, hdr->addr2, ETH_ALEN); 619 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN); 620 621 ccmp_gcmp_aad(skb, aad, spp_amsdu, aad_nonce_computed); 622 } 623 624 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id) 625 { 626 hdr[0] = pn[5]; 627 hdr[1] = pn[4]; 628 hdr[2] = 0; 629 hdr[3] = 0x20 | (key_id << 6); 630 hdr[4] = pn[3]; 631 hdr[5] = pn[2]; 632 hdr[6] = pn[1]; 633 hdr[7] = pn[0]; 634 } 635 636 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr) 637 { 638 pn[0] = hdr[7]; 639 pn[1] = hdr[6]; 640 pn[2] = hdr[5]; 641 pn[3] = hdr[4]; 642 pn[4] = hdr[1]; 643 pn[5] = hdr[0]; 644 } 645 646 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 647 { 648 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 649 struct ieee80211_key *key = tx->key; 650 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 651 int hdrlen, len, tail; 652 u8 *pos; 653 u8 pn[6]; 654 u64 pn64; 655 u8 aad[GCM_AAD_LEN]; 656 u8 j_0[AES_BLOCK_SIZE]; 657 658 if (info->control.hw_key && 659 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 660 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && 661 !((info->control.hw_key->flags & 662 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && 663 ieee80211_is_mgmt(hdr->frame_control))) { 664 /* hwaccel has no need for preallocated room for GCMP 665 * header or MIC fields 666 */ 667 return 0; 668 } 669 670 hdrlen = ieee80211_hdrlen(hdr->frame_control); 671 len = skb->len - hdrlen; 672 673 if (info->control.hw_key) 674 tail = 0; 675 else 676 tail = IEEE80211_GCMP_MIC_LEN; 677 678 if (WARN_ON(skb_tailroom(skb) < tail || 679 skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN)) 680 return -1; 681 682 pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN); 683 memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen); 684 skb_set_network_header(skb, skb_network_offset(skb) + 685 IEEE80211_GCMP_HDR_LEN); 686 687 /* the HW only needs room for the IV, but not the actual IV */ 688 if (info->control.hw_key && 689 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) 690 return 0; 691 692 pos += hdrlen; 693 694 pn64 = atomic64_inc_return(&key->conf.tx_pn); 695 696 pn[5] = pn64; 697 pn[4] = pn64 >> 8; 698 pn[3] = pn64 >> 16; 699 pn[2] = pn64 >> 24; 700 pn[1] = pn64 >> 32; 701 pn[0] = pn64 >> 40; 702 703 gcmp_pn2hdr(pos, pn, key->conf.keyidx); 704 705 /* hwaccel - with software GCMP header */ 706 if (info->control.hw_key) 707 return 0; 708 709 pos += IEEE80211_GCMP_HDR_LEN; 710 gcmp_special_blocks(skb, pn, j_0, aad, 711 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU, 712 false); 713 return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len, 714 skb_put(skb, IEEE80211_GCMP_MIC_LEN)); 715 } 716 717 ieee80211_tx_result 718 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx) 719 { 720 struct sk_buff *skb; 721 722 ieee80211_tx_set_protected(tx); 723 724 skb_queue_walk(&tx->skbs, skb) { 725 if (gcmp_encrypt_skb(tx, skb) < 0) 726 return TX_DROP; 727 } 728 729 return TX_CONTINUE; 730 } 731 732 ieee80211_rx_result 733 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx) 734 { 735 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 736 int hdrlen; 737 struct ieee80211_key *key = rx->key; 738 struct sk_buff *skb = rx->skb; 739 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 740 u8 pn[IEEE80211_GCMP_PN_LEN]; 741 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN; 742 743 hdrlen = ieee80211_hdrlen(hdr->frame_control); 744 745 if (!ieee80211_is_data(hdr->frame_control) && 746 !ieee80211_is_robust_mgmt_frame(skb) && 747 !ieee80211_require_encrypted_assoc(hdr->frame_control, rx->sta)) 748 return RX_CONTINUE; 749 750 if (status->flag & RX_FLAG_DECRYPTED) { 751 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN)) 752 return RX_DROP_U_SHORT_GCMP; 753 if (status->flag & RX_FLAG_MIC_STRIPPED) 754 mic_len = 0; 755 } else { 756 if (skb_linearize(rx->skb)) 757 return RX_DROP_U_OOM; 758 } 759 760 /* reload hdr - skb might have been reallocated */ 761 hdr = (void *)rx->skb->data; 762 763 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len; 764 if (!rx->sta || data_len < 0) 765 return RX_DROP_U_SHORT_GCMP; 766 767 if (!(status->flag & RX_FLAG_PN_VALIDATED)) { 768 int res; 769 770 gcmp_hdr2pn(pn, skb->data + hdrlen); 771 772 queue = rx->security_idx; 773 774 res = memcmp(pn, key->u.gcmp.rx_pn[queue], 775 IEEE80211_GCMP_PN_LEN); 776 if (res < 0 || 777 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) { 778 key->u.gcmp.replays++; 779 return RX_DROP_U_REPLAY; 780 } 781 782 if (!(status->flag & RX_FLAG_DECRYPTED)) { 783 u8 aad[2 * AES_BLOCK_SIZE]; 784 u8 j_0[AES_BLOCK_SIZE]; 785 bool aad_nonce_computed = false; 786 787 if (is_unicast_ether_addr(hdr->addr1) && 788 !ieee80211_is_data(hdr->frame_control)) { 789 /* AAD computation */ 790 memcpy(&aad[4], rx->link_addrs, 3 * ETH_ALEN); 791 /* Nonce computation */ 792 ether_addr_copy(&j_0[0], 793 &rx->link_addrs[ETH_ALEN]); 794 aad_nonce_computed = true; 795 } 796 /* hardware didn't decrypt/verify MIC */ 797 gcmp_special_blocks(skb, pn, j_0, aad, 798 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU, 799 aad_nonce_computed); 800 801 if (ieee80211_aes_gcm_decrypt( 802 key->u.gcmp.tfm, j_0, aad, 803 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN, 804 data_len, 805 skb->data + skb->len - 806 IEEE80211_GCMP_MIC_LEN)) 807 return RX_DROP_U_MIC_FAIL; 808 } 809 810 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN); 811 if (unlikely(ieee80211_is_frag(hdr))) 812 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN); 813 } 814 815 /* Remove GCMP header and MIC */ 816 if (pskb_trim(skb, skb->len - mic_len)) 817 return RX_DROP_U_SHORT_GCMP_MIC; 818 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen); 819 skb_pull(skb, IEEE80211_GCMP_HDR_LEN); 820 821 return RX_CONTINUE; 822 } 823 824 static void bip_aad(struct sk_buff *skb, u8 *aad) 825 { 826 __le16 mask_fc; 827 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 828 829 /* BIP AAD: FC(masked) || A1 || A2 || A3 */ 830 831 /* FC type/subtype */ 832 /* Mask FC Retry, PwrMgt, MoreData flags to zero */ 833 mask_fc = hdr->frame_control; 834 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM | 835 IEEE80211_FCTL_MOREDATA); 836 put_unaligned(mask_fc, (__le16 *) &aad[0]); 837 /* A1 || A2 || A3 */ 838 memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN); 839 } 840 841 842 static inline void bip_ipn_set64(u8 *d, u64 pn) 843 { 844 *d++ = pn; 845 *d++ = pn >> 8; 846 *d++ = pn >> 16; 847 *d++ = pn >> 24; 848 *d++ = pn >> 32; 849 *d = pn >> 40; 850 } 851 852 static inline void bip_ipn_swap(u8 *d, const u8 *s) 853 { 854 *d++ = s[5]; 855 *d++ = s[4]; 856 *d++ = s[3]; 857 *d++ = s[2]; 858 *d++ = s[1]; 859 *d = s[0]; 860 } 861 862 863 ieee80211_tx_result 864 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx, 865 unsigned int mic_len) 866 { 867 struct sk_buff *skb; 868 struct ieee80211_tx_info *info; 869 struct ieee80211_key *key = tx->key; 870 struct ieee80211_mmie_var *mmie; 871 size_t mmie_len; 872 u8 aad[20]; 873 u64 pn64; 874 875 if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) 876 return TX_DROP; 877 878 skb = skb_peek(&tx->skbs); 879 880 info = IEEE80211_SKB_CB(skb); 881 882 if (info->control.hw_key && 883 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE)) 884 return TX_CONTINUE; 885 886 mmie_len = sizeof(*mmie) + mic_len; 887 888 if (WARN_ON(skb_tailroom(skb) < mmie_len)) 889 return TX_DROP; 890 891 mmie = skb_put(skb, mmie_len); 892 mmie->element_id = WLAN_EID_MMIE; 893 mmie->length = mmie_len - 2; 894 mmie->key_id = cpu_to_le16(key->conf.keyidx); 895 896 /* PN = PN + 1 */ 897 pn64 = atomic64_inc_return(&key->conf.tx_pn); 898 899 bip_ipn_set64(mmie->sequence_number, pn64); 900 901 if (info->control.hw_key) 902 return TX_CONTINUE; 903 904 bip_aad(skb, aad); 905 906 if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 907 skb->data + 24, skb->len - 24, 908 mmie->mic, mic_len)) 909 return TX_DROP; 910 911 return TX_CONTINUE; 912 } 913 914 ieee80211_rx_result 915 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx, 916 unsigned int mic_len) 917 { 918 struct sk_buff *skb = rx->skb; 919 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 920 struct ieee80211_key *key = rx->key; 921 struct ieee80211_mmie_var *mmie; 922 size_t mmie_len; 923 u8 aad[20], mic[IEEE80211_CMAC_256_MIC_LEN], ipn[6]; 924 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 925 926 if (!ieee80211_is_mgmt(hdr->frame_control)) 927 return RX_CONTINUE; 928 929 mmie_len = sizeof(*mmie) + mic_len; 930 931 /* management frames are already linear */ 932 933 if (skb->len < 24 + mmie_len) 934 return mic_len == IEEE80211_CMAC_128_MIC_LEN ? 935 RX_DROP_U_SHORT_CMAC : RX_DROP_U_SHORT_CMAC256; 936 937 mmie = (struct ieee80211_mmie_var *)(skb->data + skb->len - mmie_len); 938 if (mmie->element_id != WLAN_EID_MMIE || 939 mmie->length != mmie_len - 2) 940 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */ 941 942 bip_ipn_swap(ipn, mmie->sequence_number); 943 944 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 945 key->u.aes_cmac.replays++; 946 return RX_DROP_U_REPLAY; 947 } 948 949 if (!(status->flag & RX_FLAG_DECRYPTED)) { 950 /* hardware didn't decrypt/verify MIC */ 951 bip_aad(skb, aad); 952 if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 953 skb->data + 24, skb->len - 24, 954 mic, mic_len)) 955 return RX_DROP_U_DECRYPT_FAIL; 956 if (crypto_memneq(mic, mmie->mic, mic_len)) { 957 key->u.aes_cmac.icverrors++; 958 return RX_DROP_U_MIC_FAIL; 959 } 960 } 961 962 memcpy(key->u.aes_cmac.rx_pn, ipn, 6); 963 964 /* Remove MMIE */ 965 skb_trim(skb, skb->len - mmie_len); 966 967 return RX_CONTINUE; 968 } 969 970 ieee80211_tx_result 971 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx) 972 { 973 struct sk_buff *skb; 974 struct ieee80211_tx_info *info; 975 struct ieee80211_key *key = tx->key; 976 struct ieee80211_mmie_16 *mmie; 977 struct ieee80211_hdr *hdr; 978 u8 aad[GMAC_AAD_LEN]; 979 u64 pn64; 980 u8 nonce[GMAC_NONCE_LEN]; 981 982 if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) 983 return TX_DROP; 984 985 skb = skb_peek(&tx->skbs); 986 987 info = IEEE80211_SKB_CB(skb); 988 989 if (info->control.hw_key && 990 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE)) 991 return TX_CONTINUE; 992 993 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 994 return TX_DROP; 995 996 mmie = skb_put(skb, sizeof(*mmie)); 997 mmie->element_id = WLAN_EID_MMIE; 998 mmie->length = sizeof(*mmie) - 2; 999 mmie->key_id = cpu_to_le16(key->conf.keyidx); 1000 1001 /* PN = PN + 1 */ 1002 pn64 = atomic64_inc_return(&key->conf.tx_pn); 1003 1004 bip_ipn_set64(mmie->sequence_number, pn64); 1005 1006 if (info->control.hw_key) 1007 return TX_CONTINUE; 1008 1009 bip_aad(skb, aad); 1010 1011 hdr = (struct ieee80211_hdr *)skb->data; 1012 memcpy(nonce, hdr->addr2, ETH_ALEN); 1013 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number); 1014 1015 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */ 1016 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, 1017 skb->data + 24, skb->len - 24, mmie->mic) < 0) 1018 return TX_DROP; 1019 1020 return TX_CONTINUE; 1021 } 1022 1023 ieee80211_rx_result 1024 ieee80211_crypto_aes_gmac_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_16 *mmie; 1030 u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN]; 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_U_SHORT_GMAC; 1040 1041 mmie = (struct ieee80211_mmie_16 *) 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_U_BAD_MMIE; /* Invalid MMIE */ 1046 1047 bip_ipn_swap(ipn, mmie->sequence_number); 1048 1049 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) { 1050 key->u.aes_gmac.replays++; 1051 return RX_DROP_U_REPLAY; 1052 } 1053 1054 if (!(status->flag & RX_FLAG_DECRYPTED)) { 1055 /* hardware didn't decrypt/verify MIC */ 1056 bip_aad(skb, aad); 1057 1058 memcpy(nonce, hdr->addr2, ETH_ALEN); 1059 memcpy(nonce + ETH_ALEN, ipn, 6); 1060 1061 mic = kmalloc(IEEE80211_GMAC_MIC_LEN, GFP_ATOMIC); 1062 if (!mic) 1063 return RX_DROP_U_OOM; 1064 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, 1065 skb->data + 24, skb->len - 24, 1066 mic) < 0 || 1067 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { 1068 key->u.aes_gmac.icverrors++; 1069 kfree(mic); 1070 return RX_DROP_U_MIC_FAIL; 1071 } 1072 kfree(mic); 1073 } 1074 1075 memcpy(key->u.aes_gmac.rx_pn, ipn, 6); 1076 1077 /* Remove MMIE */ 1078 skb_trim(skb, skb->len - sizeof(*mmie)); 1079 1080 return RX_CONTINUE; 1081 } 1082