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) 2020-2022 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 <asm/unaligned.h> 16 #include <net/mac80211.h> 17 #include <crypto/aes.h> 18 #include <crypto/algapi.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_UNUSABLE; 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_UNUSABLE; 154 155 if (skb_linearize(rx->skb)) 156 return RX_DROP_UNUSABLE; 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_UNUSABLE; 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_UNUSABLE; 280 281 /* it may be possible to optimize this a bit more */ 282 if (skb_linearize(rx->skb)) 283 return RX_DROP_UNUSABLE; 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_UNUSABLE; 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) 319 { 320 struct ieee80211_hdr *hdr = (void *)skb->data; 321 __le16 mask_fc; 322 int a4_included, mgmt; 323 u8 qos_tid; 324 u16 len_a = 22; 325 326 /* 327 * Mask FC: zero subtype b4 b5 b6 (if not mgmt) 328 * Retry, PwrMgt, MoreData, Order (if Qos Data); set Protected 329 */ 330 mgmt = ieee80211_is_mgmt(hdr->frame_control); 331 mask_fc = hdr->frame_control; 332 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | 333 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); 334 if (!mgmt) 335 mask_fc &= ~cpu_to_le16(0x0070); 336 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 337 338 a4_included = ieee80211_has_a4(hdr->frame_control); 339 if (a4_included) 340 len_a += 6; 341 342 if (ieee80211_is_data_qos(hdr->frame_control)) { 343 qos_tid = ieee80211_get_tid(hdr); 344 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_ORDER); 345 len_a += 2; 346 } else { 347 qos_tid = 0; 348 } 349 350 /* AAD (extra authenticate-only data) / masked 802.11 header 351 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ 352 put_unaligned_be16(len_a, &aad[0]); 353 put_unaligned(mask_fc, (__le16 *)&aad[2]); 354 memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN); 355 356 /* Mask Seq#, leave Frag# */ 357 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; 358 aad[23] = 0; 359 360 if (a4_included) { 361 memcpy(&aad[24], hdr->addr4, ETH_ALEN); 362 aad[30] = qos_tid; 363 aad[31] = 0; 364 } else { 365 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); 366 aad[24] = qos_tid; 367 } 368 369 return qos_tid; 370 } 371 372 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad) 373 { 374 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 375 u8 qos_tid = ccmp_gcmp_aad(skb, aad); 376 377 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC 378 * mode authentication are not allowed to collide, yet both are derived 379 * from this vector b_0. We only set L := 1 here to indicate that the 380 * data size can be represented in (L+1) bytes. The CCM layer will take 381 * care of storing the data length in the top (L+1) bytes and setting 382 * and clearing the other bits as is required to derive the two IVs. 383 */ 384 b_0[0] = 0x1; 385 386 /* Nonce: Nonce Flags | A2 | PN 387 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) 388 */ 389 b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4); 390 memcpy(&b_0[2], hdr->addr2, ETH_ALEN); 391 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN); 392 } 393 394 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) 395 { 396 hdr[0] = pn[5]; 397 hdr[1] = pn[4]; 398 hdr[2] = 0; 399 hdr[3] = 0x20 | (key_id << 6); 400 hdr[4] = pn[3]; 401 hdr[5] = pn[2]; 402 hdr[6] = pn[1]; 403 hdr[7] = pn[0]; 404 } 405 406 407 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) 408 { 409 pn[0] = hdr[7]; 410 pn[1] = hdr[6]; 411 pn[2] = hdr[5]; 412 pn[3] = hdr[4]; 413 pn[4] = hdr[1]; 414 pn[5] = hdr[0]; 415 } 416 417 418 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb, 419 unsigned int mic_len) 420 { 421 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 422 struct ieee80211_key *key = tx->key; 423 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 424 int hdrlen, len, tail; 425 u8 *pos; 426 u8 pn[6]; 427 u64 pn64; 428 u8 aad[CCM_AAD_LEN]; 429 u8 b_0[AES_BLOCK_SIZE]; 430 431 if (info->control.hw_key && 432 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 433 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && 434 !((info->control.hw_key->flags & 435 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && 436 ieee80211_is_mgmt(hdr->frame_control))) { 437 /* 438 * hwaccel has no need for preallocated room for CCMP 439 * header or MIC fields 440 */ 441 return 0; 442 } 443 444 hdrlen = ieee80211_hdrlen(hdr->frame_control); 445 len = skb->len - hdrlen; 446 447 if (info->control.hw_key) 448 tail = 0; 449 else 450 tail = mic_len; 451 452 if (WARN_ON(skb_tailroom(skb) < tail || 453 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN)) 454 return -1; 455 456 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN); 457 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen); 458 459 /* the HW only needs room for the IV, but not the actual IV */ 460 if (info->control.hw_key && 461 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) 462 return 0; 463 464 pos += hdrlen; 465 466 pn64 = atomic64_inc_return(&key->conf.tx_pn); 467 468 pn[5] = pn64; 469 pn[4] = pn64 >> 8; 470 pn[3] = pn64 >> 16; 471 pn[2] = pn64 >> 24; 472 pn[1] = pn64 >> 32; 473 pn[0] = pn64 >> 40; 474 475 ccmp_pn2hdr(pos, pn, key->conf.keyidx); 476 477 /* hwaccel - with software CCMP header */ 478 if (info->control.hw_key) 479 return 0; 480 481 pos += IEEE80211_CCMP_HDR_LEN; 482 ccmp_special_blocks(skb, pn, b_0, aad); 483 return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len, 484 skb_put(skb, mic_len)); 485 } 486 487 488 ieee80211_tx_result 489 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx, 490 unsigned int mic_len) 491 { 492 struct sk_buff *skb; 493 494 ieee80211_tx_set_protected(tx); 495 496 skb_queue_walk(&tx->skbs, skb) { 497 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0) 498 return TX_DROP; 499 } 500 501 return TX_CONTINUE; 502 } 503 504 505 ieee80211_rx_result 506 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx, 507 unsigned int mic_len) 508 { 509 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 510 int hdrlen; 511 struct ieee80211_key *key = rx->key; 512 struct sk_buff *skb = rx->skb; 513 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 514 u8 pn[IEEE80211_CCMP_PN_LEN]; 515 int data_len; 516 int queue; 517 518 hdrlen = ieee80211_hdrlen(hdr->frame_control); 519 520 if (!ieee80211_is_data(hdr->frame_control) && 521 !ieee80211_is_robust_mgmt_frame(skb)) 522 return RX_CONTINUE; 523 524 if (status->flag & RX_FLAG_DECRYPTED) { 525 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN)) 526 return RX_DROP_UNUSABLE; 527 if (status->flag & RX_FLAG_MIC_STRIPPED) 528 mic_len = 0; 529 } else { 530 if (skb_linearize(rx->skb)) 531 return RX_DROP_UNUSABLE; 532 } 533 534 /* reload hdr - skb might have been reallocated */ 535 hdr = (void *)rx->skb->data; 536 537 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len; 538 if (!rx->sta || data_len < 0) 539 return RX_DROP_UNUSABLE; 540 541 if (!(status->flag & RX_FLAG_PN_VALIDATED)) { 542 int res; 543 544 ccmp_hdr2pn(pn, skb->data + hdrlen); 545 546 queue = rx->security_idx; 547 548 res = memcmp(pn, key->u.ccmp.rx_pn[queue], 549 IEEE80211_CCMP_PN_LEN); 550 if (res < 0 || 551 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) { 552 key->u.ccmp.replays++; 553 return RX_DROP_UNUSABLE; 554 } 555 556 if (!(status->flag & RX_FLAG_DECRYPTED)) { 557 u8 aad[2 * AES_BLOCK_SIZE]; 558 u8 b_0[AES_BLOCK_SIZE]; 559 /* hardware didn't decrypt/verify MIC */ 560 ccmp_special_blocks(skb, pn, b_0, aad); 561 562 if (ieee80211_aes_ccm_decrypt( 563 key->u.ccmp.tfm, b_0, aad, 564 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN, 565 data_len, 566 skb->data + skb->len - mic_len)) 567 return RX_DROP_UNUSABLE; 568 } 569 570 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN); 571 if (unlikely(ieee80211_is_frag(hdr))) 572 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN); 573 } 574 575 /* Remove CCMP header and MIC */ 576 if (pskb_trim(skb, skb->len - mic_len)) 577 return RX_DROP_UNUSABLE; 578 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen); 579 skb_pull(skb, IEEE80211_CCMP_HDR_LEN); 580 581 return RX_CONTINUE; 582 } 583 584 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad) 585 { 586 struct ieee80211_hdr *hdr = (void *)skb->data; 587 588 memcpy(j_0, hdr->addr2, ETH_ALEN); 589 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN); 590 j_0[13] = 0; 591 j_0[14] = 0; 592 j_0[AES_BLOCK_SIZE - 1] = 0x01; 593 594 ccmp_gcmp_aad(skb, aad); 595 } 596 597 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id) 598 { 599 hdr[0] = pn[5]; 600 hdr[1] = pn[4]; 601 hdr[2] = 0; 602 hdr[3] = 0x20 | (key_id << 6); 603 hdr[4] = pn[3]; 604 hdr[5] = pn[2]; 605 hdr[6] = pn[1]; 606 hdr[7] = pn[0]; 607 } 608 609 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr) 610 { 611 pn[0] = hdr[7]; 612 pn[1] = hdr[6]; 613 pn[2] = hdr[5]; 614 pn[3] = hdr[4]; 615 pn[4] = hdr[1]; 616 pn[5] = hdr[0]; 617 } 618 619 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 620 { 621 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 622 struct ieee80211_key *key = tx->key; 623 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 624 int hdrlen, len, tail; 625 u8 *pos; 626 u8 pn[6]; 627 u64 pn64; 628 u8 aad[GCM_AAD_LEN]; 629 u8 j_0[AES_BLOCK_SIZE]; 630 631 if (info->control.hw_key && 632 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && 633 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && 634 !((info->control.hw_key->flags & 635 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && 636 ieee80211_is_mgmt(hdr->frame_control))) { 637 /* hwaccel has no need for preallocated room for GCMP 638 * header or MIC fields 639 */ 640 return 0; 641 } 642 643 hdrlen = ieee80211_hdrlen(hdr->frame_control); 644 len = skb->len - hdrlen; 645 646 if (info->control.hw_key) 647 tail = 0; 648 else 649 tail = IEEE80211_GCMP_MIC_LEN; 650 651 if (WARN_ON(skb_tailroom(skb) < tail || 652 skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN)) 653 return -1; 654 655 pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN); 656 memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen); 657 skb_set_network_header(skb, skb_network_offset(skb) + 658 IEEE80211_GCMP_HDR_LEN); 659 660 /* the HW only needs room for the IV, but not the actual IV */ 661 if (info->control.hw_key && 662 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) 663 return 0; 664 665 pos += hdrlen; 666 667 pn64 = atomic64_inc_return(&key->conf.tx_pn); 668 669 pn[5] = pn64; 670 pn[4] = pn64 >> 8; 671 pn[3] = pn64 >> 16; 672 pn[2] = pn64 >> 24; 673 pn[1] = pn64 >> 32; 674 pn[0] = pn64 >> 40; 675 676 gcmp_pn2hdr(pos, pn, key->conf.keyidx); 677 678 /* hwaccel - with software GCMP header */ 679 if (info->control.hw_key) 680 return 0; 681 682 pos += IEEE80211_GCMP_HDR_LEN; 683 gcmp_special_blocks(skb, pn, j_0, aad); 684 return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len, 685 skb_put(skb, IEEE80211_GCMP_MIC_LEN)); 686 } 687 688 ieee80211_tx_result 689 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx) 690 { 691 struct sk_buff *skb; 692 693 ieee80211_tx_set_protected(tx); 694 695 skb_queue_walk(&tx->skbs, skb) { 696 if (gcmp_encrypt_skb(tx, skb) < 0) 697 return TX_DROP; 698 } 699 700 return TX_CONTINUE; 701 } 702 703 ieee80211_rx_result 704 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx) 705 { 706 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; 707 int hdrlen; 708 struct ieee80211_key *key = rx->key; 709 struct sk_buff *skb = rx->skb; 710 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 711 u8 pn[IEEE80211_GCMP_PN_LEN]; 712 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN; 713 714 hdrlen = ieee80211_hdrlen(hdr->frame_control); 715 716 if (!ieee80211_is_data(hdr->frame_control) && 717 !ieee80211_is_robust_mgmt_frame(skb)) 718 return RX_CONTINUE; 719 720 if (status->flag & RX_FLAG_DECRYPTED) { 721 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN)) 722 return RX_DROP_UNUSABLE; 723 if (status->flag & RX_FLAG_MIC_STRIPPED) 724 mic_len = 0; 725 } else { 726 if (skb_linearize(rx->skb)) 727 return RX_DROP_UNUSABLE; 728 } 729 730 /* reload hdr - skb might have been reallocated */ 731 hdr = (void *)rx->skb->data; 732 733 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len; 734 if (!rx->sta || data_len < 0) 735 return RX_DROP_UNUSABLE; 736 737 if (!(status->flag & RX_FLAG_PN_VALIDATED)) { 738 int res; 739 740 gcmp_hdr2pn(pn, skb->data + hdrlen); 741 742 queue = rx->security_idx; 743 744 res = memcmp(pn, key->u.gcmp.rx_pn[queue], 745 IEEE80211_GCMP_PN_LEN); 746 if (res < 0 || 747 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) { 748 key->u.gcmp.replays++; 749 return RX_DROP_UNUSABLE; 750 } 751 752 if (!(status->flag & RX_FLAG_DECRYPTED)) { 753 u8 aad[2 * AES_BLOCK_SIZE]; 754 u8 j_0[AES_BLOCK_SIZE]; 755 /* hardware didn't decrypt/verify MIC */ 756 gcmp_special_blocks(skb, pn, j_0, aad); 757 758 if (ieee80211_aes_gcm_decrypt( 759 key->u.gcmp.tfm, j_0, aad, 760 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN, 761 data_len, 762 skb->data + skb->len - 763 IEEE80211_GCMP_MIC_LEN)) 764 return RX_DROP_UNUSABLE; 765 } 766 767 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN); 768 if (unlikely(ieee80211_is_frag(hdr))) 769 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN); 770 } 771 772 /* Remove GCMP header and MIC */ 773 if (pskb_trim(skb, skb->len - mic_len)) 774 return RX_DROP_UNUSABLE; 775 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen); 776 skb_pull(skb, IEEE80211_GCMP_HDR_LEN); 777 778 return RX_CONTINUE; 779 } 780 781 static void bip_aad(struct sk_buff *skb, u8 *aad) 782 { 783 __le16 mask_fc; 784 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 785 786 /* BIP AAD: FC(masked) || A1 || A2 || A3 */ 787 788 /* FC type/subtype */ 789 /* Mask FC Retry, PwrMgt, MoreData flags to zero */ 790 mask_fc = hdr->frame_control; 791 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM | 792 IEEE80211_FCTL_MOREDATA); 793 put_unaligned(mask_fc, (__le16 *) &aad[0]); 794 /* A1 || A2 || A3 */ 795 memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN); 796 } 797 798 799 static inline void bip_ipn_set64(u8 *d, u64 pn) 800 { 801 *d++ = pn; 802 *d++ = pn >> 8; 803 *d++ = pn >> 16; 804 *d++ = pn >> 24; 805 *d++ = pn >> 32; 806 *d = pn >> 40; 807 } 808 809 static inline void bip_ipn_swap(u8 *d, const u8 *s) 810 { 811 *d++ = s[5]; 812 *d++ = s[4]; 813 *d++ = s[3]; 814 *d++ = s[2]; 815 *d++ = s[1]; 816 *d = s[0]; 817 } 818 819 820 ieee80211_tx_result 821 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) 822 { 823 struct sk_buff *skb; 824 struct ieee80211_tx_info *info; 825 struct ieee80211_key *key = tx->key; 826 struct ieee80211_mmie *mmie; 827 u8 aad[20]; 828 u64 pn64; 829 830 if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) 831 return TX_DROP; 832 833 skb = skb_peek(&tx->skbs); 834 835 info = IEEE80211_SKB_CB(skb); 836 837 if (info->control.hw_key && 838 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE)) 839 return TX_CONTINUE; 840 841 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 842 return TX_DROP; 843 844 mmie = skb_put(skb, sizeof(*mmie)); 845 mmie->element_id = WLAN_EID_MMIE; 846 mmie->length = sizeof(*mmie) - 2; 847 mmie->key_id = cpu_to_le16(key->conf.keyidx); 848 849 /* PN = PN + 1 */ 850 pn64 = atomic64_inc_return(&key->conf.tx_pn); 851 852 bip_ipn_set64(mmie->sequence_number, pn64); 853 854 if (info->control.hw_key) 855 return TX_CONTINUE; 856 857 bip_aad(skb, aad); 858 859 /* 860 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) 861 */ 862 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 863 skb->data + 24, skb->len - 24, mmie->mic); 864 865 return TX_CONTINUE; 866 } 867 868 ieee80211_tx_result 869 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx) 870 { 871 struct sk_buff *skb; 872 struct ieee80211_tx_info *info; 873 struct ieee80211_key *key = tx->key; 874 struct ieee80211_mmie_16 *mmie; 875 u8 aad[20]; 876 u64 pn64; 877 878 if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) 879 return TX_DROP; 880 881 skb = skb_peek(&tx->skbs); 882 883 info = IEEE80211_SKB_CB(skb); 884 885 if (info->control.hw_key) 886 return TX_CONTINUE; 887 888 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 889 return TX_DROP; 890 891 mmie = skb_put(skb, sizeof(*mmie)); 892 mmie->element_id = WLAN_EID_MMIE; 893 mmie->length = sizeof(*mmie) - 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 bip_aad(skb, aad); 902 903 /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128) 904 */ 905 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad, 906 skb->data + 24, skb->len - 24, mmie->mic); 907 908 return TX_CONTINUE; 909 } 910 911 ieee80211_rx_result 912 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 913 { 914 struct sk_buff *skb = rx->skb; 915 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 916 struct ieee80211_key *key = rx->key; 917 struct ieee80211_mmie *mmie; 918 u8 aad[20], mic[8], ipn[6]; 919 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 920 921 if (!ieee80211_is_mgmt(hdr->frame_control)) 922 return RX_CONTINUE; 923 924 /* management frames are already linear */ 925 926 if (skb->len < 24 + sizeof(*mmie)) 927 return RX_DROP_UNUSABLE; 928 929 mmie = (struct ieee80211_mmie *) 930 (skb->data + skb->len - sizeof(*mmie)); 931 if (mmie->element_id != WLAN_EID_MMIE || 932 mmie->length != sizeof(*mmie) - 2) 933 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 934 935 bip_ipn_swap(ipn, mmie->sequence_number); 936 937 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 938 key->u.aes_cmac.replays++; 939 return RX_DROP_UNUSABLE; 940 } 941 942 if (!(status->flag & RX_FLAG_DECRYPTED)) { 943 /* hardware didn't decrypt/verify MIC */ 944 bip_aad(skb, aad); 945 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, 946 skb->data + 24, skb->len - 24, mic); 947 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { 948 key->u.aes_cmac.icverrors++; 949 return RX_DROP_UNUSABLE; 950 } 951 } 952 953 memcpy(key->u.aes_cmac.rx_pn, ipn, 6); 954 955 /* Remove MMIE */ 956 skb_trim(skb, skb->len - sizeof(*mmie)); 957 958 return RX_CONTINUE; 959 } 960 961 ieee80211_rx_result 962 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx) 963 { 964 struct sk_buff *skb = rx->skb; 965 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 966 struct ieee80211_key *key = rx->key; 967 struct ieee80211_mmie_16 *mmie; 968 u8 aad[20], mic[16], ipn[6]; 969 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 970 971 if (!ieee80211_is_mgmt(hdr->frame_control)) 972 return RX_CONTINUE; 973 974 /* management frames are already linear */ 975 976 if (skb->len < 24 + sizeof(*mmie)) 977 return RX_DROP_UNUSABLE; 978 979 mmie = (struct ieee80211_mmie_16 *) 980 (skb->data + skb->len - sizeof(*mmie)); 981 if (mmie->element_id != WLAN_EID_MMIE || 982 mmie->length != sizeof(*mmie) - 2) 983 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 984 985 bip_ipn_swap(ipn, mmie->sequence_number); 986 987 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { 988 key->u.aes_cmac.replays++; 989 return RX_DROP_UNUSABLE; 990 } 991 992 if (!(status->flag & RX_FLAG_DECRYPTED)) { 993 /* hardware didn't decrypt/verify MIC */ 994 bip_aad(skb, aad); 995 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad, 996 skb->data + 24, skb->len - 24, mic); 997 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { 998 key->u.aes_cmac.icverrors++; 999 return RX_DROP_UNUSABLE; 1000 } 1001 } 1002 1003 memcpy(key->u.aes_cmac.rx_pn, ipn, 6); 1004 1005 /* Remove MMIE */ 1006 skb_trim(skb, skb->len - sizeof(*mmie)); 1007 1008 return RX_CONTINUE; 1009 } 1010 1011 ieee80211_tx_result 1012 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx) 1013 { 1014 struct sk_buff *skb; 1015 struct ieee80211_tx_info *info; 1016 struct ieee80211_key *key = tx->key; 1017 struct ieee80211_mmie_16 *mmie; 1018 struct ieee80211_hdr *hdr; 1019 u8 aad[GMAC_AAD_LEN]; 1020 u64 pn64; 1021 u8 nonce[GMAC_NONCE_LEN]; 1022 1023 if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) 1024 return TX_DROP; 1025 1026 skb = skb_peek(&tx->skbs); 1027 1028 info = IEEE80211_SKB_CB(skb); 1029 1030 if (info->control.hw_key) 1031 return TX_CONTINUE; 1032 1033 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) 1034 return TX_DROP; 1035 1036 mmie = skb_put(skb, sizeof(*mmie)); 1037 mmie->element_id = WLAN_EID_MMIE; 1038 mmie->length = sizeof(*mmie) - 2; 1039 mmie->key_id = cpu_to_le16(key->conf.keyidx); 1040 1041 /* PN = PN + 1 */ 1042 pn64 = atomic64_inc_return(&key->conf.tx_pn); 1043 1044 bip_ipn_set64(mmie->sequence_number, pn64); 1045 1046 bip_aad(skb, aad); 1047 1048 hdr = (struct ieee80211_hdr *)skb->data; 1049 memcpy(nonce, hdr->addr2, ETH_ALEN); 1050 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number); 1051 1052 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */ 1053 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, 1054 skb->data + 24, skb->len - 24, mmie->mic) < 0) 1055 return TX_DROP; 1056 1057 return TX_CONTINUE; 1058 } 1059 1060 ieee80211_rx_result 1061 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx) 1062 { 1063 struct sk_buff *skb = rx->skb; 1064 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); 1065 struct ieee80211_key *key = rx->key; 1066 struct ieee80211_mmie_16 *mmie; 1067 u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN]; 1068 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 1069 1070 if (!ieee80211_is_mgmt(hdr->frame_control)) 1071 return RX_CONTINUE; 1072 1073 /* management frames are already linear */ 1074 1075 if (skb->len < 24 + sizeof(*mmie)) 1076 return RX_DROP_UNUSABLE; 1077 1078 mmie = (struct ieee80211_mmie_16 *) 1079 (skb->data + skb->len - sizeof(*mmie)); 1080 if (mmie->element_id != WLAN_EID_MMIE || 1081 mmie->length != sizeof(*mmie) - 2) 1082 return RX_DROP_UNUSABLE; /* Invalid MMIE */ 1083 1084 bip_ipn_swap(ipn, mmie->sequence_number); 1085 1086 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) { 1087 key->u.aes_gmac.replays++; 1088 return RX_DROP_UNUSABLE; 1089 } 1090 1091 if (!(status->flag & RX_FLAG_DECRYPTED)) { 1092 /* hardware didn't decrypt/verify MIC */ 1093 bip_aad(skb, aad); 1094 1095 memcpy(nonce, hdr->addr2, ETH_ALEN); 1096 memcpy(nonce + ETH_ALEN, ipn, 6); 1097 1098 mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC); 1099 if (!mic) 1100 return RX_DROP_UNUSABLE; 1101 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, 1102 skb->data + 24, skb->len - 24, 1103 mic) < 0 || 1104 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) { 1105 key->u.aes_gmac.icverrors++; 1106 kfree(mic); 1107 return RX_DROP_UNUSABLE; 1108 } 1109 kfree(mic); 1110 } 1111 1112 memcpy(key->u.aes_gmac.rx_pn, ipn, 6); 1113 1114 /* Remove MMIE */ 1115 skb_trim(skb, skb->len - sizeof(*mmie)); 1116 1117 return RX_CONTINUE; 1118 } 1119