1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (c) 2017, Linaro Limited 4 */ 5 6 #include <assert.h> 7 #include <config.h> 8 #include <crypto/crypto.h> 9 #include <initcall.h> 10 #include <kernel/tee_common_otp.h> 11 #include <stdlib.h> 12 #include <string_ext.h> 13 #include <string.h> 14 #include <tee/fs_htree.h> 15 #include <tee/tee_fs_key_manager.h> 16 #include <tee/tee_fs_rpc.h> 17 #include <utee_defines.h> 18 #include <util.h> 19 20 #define TEE_FS_HTREE_CHIP_ID_SIZE 32 21 #define TEE_FS_HTREE_HASH_ALG TEE_ALG_SHA256 22 #define TEE_FS_HTREE_TSK_SIZE TEE_FS_HTREE_HASH_SIZE 23 #define TEE_FS_HTREE_ENC_ALG TEE_ALG_AES_ECB_NOPAD 24 #define TEE_FS_HTREE_ENC_SIZE TEE_AES_BLOCK_SIZE 25 #define TEE_FS_HTREE_SSK_SIZE TEE_FS_HTREE_HASH_SIZE 26 27 #define TEE_FS_HTREE_AUTH_ENC_ALG TEE_ALG_AES_GCM 28 #define TEE_FS_HTREE_HMAC_ALG TEE_ALG_HMAC_SHA256 29 30 #define BLOCK_NUM_TO_NODE_ID(num) ((num) + 1) 31 32 #define NODE_ID_TO_BLOCK_NUM(id) ((id) - 1) 33 34 /* 35 * The hash tree is implemented as a binary tree with the purpose to ensure 36 * integrity of the data in the nodes. The data in the nodes their turn 37 * provides both integrity and confidentiality of the data blocks. 38 * 39 * The hash tree is saved in a file as: 40 * +----------------------------+ 41 * | htree_image.0 | 42 * | htree_image.1 | 43 * +----------------------------+ 44 * | htree_node_image.1.0 | 45 * | htree_node_image.1.1 | 46 * +----------------------------+ 47 * | htree_node_image.2.0 | 48 * | htree_node_image.2.1 | 49 * +----------------------------+ 50 * | htree_node_image.3.0 | 51 * | htree_node_image.3.1 | 52 * +----------------------------+ 53 * | htree_node_image.4.0 | 54 * | htree_node_image.4.1 | 55 * +----------------------------+ 56 * ... 57 * 58 * htree_image is the header of the file, there's two instances of it. One 59 * which is committed and the other is used when updating the file. Which 60 * is committed is indicated by the "counter" field, the one with the 61 * largest value is selected. 62 * 63 * htree_node_image is a node in the hash tree, each node has two instances 64 * which is committed is decided by the parent node .flag bit 65 * HTREE_NODE_COMMITTED_CHILD. Which version is the committed version of 66 * node 1 is determined by the by the lowest bit of the counter field in 67 * the header. 68 * 69 * Note that nodes start counting at 1 while blocks at 0, this means that 70 * block 0 is represented by node 1. 71 * 72 * Where different elements are stored in the file is managed by the file 73 * system. 74 */ 75 76 #define HTREE_NODE_COMMITTED_BLOCK BIT32(0) 77 /* n is 0 or 1 */ 78 #define HTREE_NODE_COMMITTED_CHILD(n) BIT32(1 + (n)) 79 80 struct htree_node { 81 size_t id; 82 bool dirty; 83 bool block_updated; 84 struct tee_fs_htree_node_image node; 85 struct htree_node *parent; 86 struct htree_node *child[2]; 87 }; 88 89 struct tee_fs_htree { 90 struct htree_node root; 91 struct tee_fs_htree_image head; 92 uint8_t fek[TEE_FS_HTREE_FEK_SIZE]; 93 struct tee_fs_htree_imeta imeta; 94 bool dirty; 95 const TEE_UUID *uuid; 96 const struct tee_fs_htree_storage *stor; 97 void *stor_aux; 98 }; 99 100 struct traverse_arg; 101 typedef TEE_Result (*traverse_cb_t)(struct traverse_arg *targ, 102 struct htree_node *node); 103 struct traverse_arg { 104 struct tee_fs_htree *ht; 105 traverse_cb_t cb; 106 void *arg; 107 }; 108 109 static TEE_Result rpc_read(struct tee_fs_htree *ht, enum tee_fs_htree_type type, 110 size_t idx, size_t vers, void *data, size_t dlen) 111 { 112 TEE_Result res; 113 struct tee_fs_rpc_operation op; 114 size_t bytes; 115 void *p; 116 117 res = ht->stor->rpc_read_init(ht->stor_aux, &op, type, idx, vers, &p); 118 if (res != TEE_SUCCESS) 119 return res; 120 121 res = ht->stor->rpc_read_final(&op, &bytes); 122 if (res != TEE_SUCCESS) 123 return res; 124 125 if (bytes != dlen) 126 return TEE_ERROR_CORRUPT_OBJECT; 127 128 memcpy(data, p, dlen); 129 return TEE_SUCCESS; 130 } 131 132 static TEE_Result rpc_read_head(struct tee_fs_htree *ht, size_t vers, 133 struct tee_fs_htree_image *head) 134 { 135 return rpc_read(ht, TEE_FS_HTREE_TYPE_HEAD, 0, vers, 136 head, sizeof(*head)); 137 } 138 139 static TEE_Result rpc_read_node(struct tee_fs_htree *ht, size_t node_id, 140 size_t vers, 141 struct tee_fs_htree_node_image *node) 142 { 143 return rpc_read(ht, TEE_FS_HTREE_TYPE_NODE, node_id - 1, vers, 144 node, sizeof(*node)); 145 } 146 147 static TEE_Result rpc_write(struct tee_fs_htree *ht, 148 enum tee_fs_htree_type type, size_t idx, 149 size_t vers, const void *data, size_t dlen) 150 { 151 TEE_Result res; 152 struct tee_fs_rpc_operation op; 153 void *p; 154 155 res = ht->stor->rpc_write_init(ht->stor_aux, &op, type, idx, vers, &p); 156 if (res != TEE_SUCCESS) 157 return res; 158 159 memcpy(p, data, dlen); 160 return ht->stor->rpc_write_final(&op); 161 } 162 163 static TEE_Result rpc_write_head(struct tee_fs_htree *ht, size_t vers, 164 const struct tee_fs_htree_image *head) 165 { 166 return rpc_write(ht, TEE_FS_HTREE_TYPE_HEAD, 0, vers, 167 head, sizeof(*head)); 168 } 169 170 static TEE_Result rpc_write_node(struct tee_fs_htree *ht, size_t node_id, 171 size_t vers, 172 const struct tee_fs_htree_node_image *node) 173 { 174 return rpc_write(ht, TEE_FS_HTREE_TYPE_NODE, node_id - 1, vers, 175 node, sizeof(*node)); 176 } 177 178 static TEE_Result traverse_post_order(struct traverse_arg *targ, 179 struct htree_node *node) 180 { 181 TEE_Result res; 182 183 /* 184 * This function is recursing but not very deep, only with Log(N) 185 * maximum depth. 186 */ 187 188 if (!node) 189 return TEE_SUCCESS; 190 191 res = traverse_post_order(targ, node->child[0]); 192 if (res != TEE_SUCCESS) 193 return res; 194 195 res = traverse_post_order(targ, node->child[1]); 196 if (res != TEE_SUCCESS) 197 return res; 198 199 return targ->cb(targ, node); 200 } 201 202 static TEE_Result htree_traverse_post_order(struct tee_fs_htree *ht, 203 traverse_cb_t cb, void *arg) 204 { 205 struct traverse_arg targ = { ht, cb, arg }; 206 207 return traverse_post_order(&targ, &ht->root); 208 } 209 210 static size_t node_id_to_level(size_t node_id) 211 { 212 assert(node_id && node_id < UINT_MAX); 213 /* Calculate level of the node, root node (1) has level 1 */ 214 return sizeof(unsigned int) * 8 - __builtin_clz(node_id); 215 } 216 217 static struct htree_node *find_closest_node(struct tee_fs_htree *ht, 218 size_t node_id) 219 { 220 struct htree_node *node = &ht->root; 221 size_t level = node_id_to_level(node_id); 222 size_t n; 223 224 /* n = 1 because root node is level 1 */ 225 for (n = 1; n < level; n++) { 226 struct htree_node *child; 227 size_t bit_idx; 228 229 /* 230 * The difference between levels of the current node and 231 * the node we're looking for tells which bit decides 232 * direction in the tree. 233 * 234 * As the first bit has index 0 we'll subtract 1 235 */ 236 bit_idx = level - n - 1; 237 child = node->child[((node_id >> bit_idx) & 1)]; 238 if (!child) 239 return node; 240 node = child; 241 } 242 243 return node; 244 } 245 246 static struct htree_node *find_node(struct tee_fs_htree *ht, size_t node_id) 247 { 248 struct htree_node *node = find_closest_node(ht, node_id); 249 250 if (node && node->id == node_id) 251 return node; 252 return NULL; 253 } 254 255 static TEE_Result get_node(struct tee_fs_htree *ht, bool create, 256 size_t node_id, struct htree_node **node_ret) 257 { 258 struct htree_node *node; 259 struct htree_node *nc; 260 size_t n; 261 262 node = find_closest_node(ht, node_id); 263 if (!node) 264 return TEE_ERROR_GENERIC; 265 if (node->id == node_id) 266 goto ret_node; 267 268 /* 269 * Trying to read beyond end of file should be caught earlier than 270 * here. 271 */ 272 if (!create) 273 return TEE_ERROR_GENERIC; 274 275 /* 276 * Add missing nodes, some nodes may already be there. When we've 277 * processed the range all nodes up to node_id will be in the tree. 278 */ 279 for (n = node->id + 1; n <= node_id; n++) { 280 node = find_closest_node(ht, n); 281 if (node->id == n) 282 continue; 283 /* Node id n should be a child of node */ 284 assert((n >> 1) == node->id); 285 assert(!node->child[n & 1]); 286 287 nc = calloc(1, sizeof(*nc)); 288 if (!nc) 289 return TEE_ERROR_OUT_OF_MEMORY; 290 nc->id = n; 291 nc->parent = node; 292 node->child[n & 1] = nc; 293 node = nc; 294 } 295 296 if (node->id > ht->imeta.max_node_id) 297 ht->imeta.max_node_id = node->id; 298 299 ret_node: 300 *node_ret = node; 301 return TEE_SUCCESS; 302 } 303 304 static int get_idx_from_counter(uint32_t counter0, uint32_t counter1) 305 { 306 if (!(counter0 & 1)) { 307 if (!(counter1 & 1)) 308 return 0; 309 if (counter0 > counter1) 310 return 0; 311 else 312 return 1; 313 } 314 315 if (counter1 & 1) 316 return 1; 317 else 318 return -1; 319 } 320 321 static TEE_Result init_head_from_data(struct tee_fs_htree *ht, 322 const uint8_t *hash, uint32_t min_counter) 323 { 324 TEE_Result res; 325 int idx; 326 327 if (hash) { 328 for (idx = 0;; idx++) { 329 res = rpc_read_node(ht, 1, idx, &ht->root.node); 330 if (res != TEE_SUCCESS) 331 return res; 332 333 if (!memcmp(ht->root.node.hash, hash, 334 sizeof(ht->root.node.hash))) { 335 res = rpc_read_head(ht, idx, &ht->head); 336 if (res != TEE_SUCCESS) 337 return res; 338 break; 339 } 340 341 if (idx) 342 return TEE_ERROR_CORRUPT_OBJECT; 343 } 344 } else { 345 struct tee_fs_htree_image head[2]; 346 347 for (idx = 0; idx < 2; idx++) { 348 res = rpc_read_head(ht, idx, head + idx); 349 if (res != TEE_SUCCESS) 350 return res; 351 } 352 353 idx = get_idx_from_counter(head[0].counter, head[1].counter); 354 if (idx < 0) 355 return TEE_ERROR_SECURITY; 356 357 res = rpc_read_node(ht, 1, idx, &ht->root.node); 358 if (res != TEE_SUCCESS) 359 return res; 360 361 ht->head = head[idx]; 362 } 363 364 if (ht->head.counter < min_counter) 365 return TEE_ERROR_SECURITY; 366 367 ht->root.id = 1; 368 369 return TEE_SUCCESS; 370 } 371 372 static TEE_Result init_tree_from_data(struct tee_fs_htree *ht) 373 { 374 TEE_Result res; 375 struct tee_fs_htree_node_image node_image; 376 struct htree_node *node; 377 struct htree_node *nc; 378 size_t committed_version; 379 size_t node_id = 2; 380 381 while (node_id <= ht->imeta.max_node_id) { 382 node = find_node(ht, node_id >> 1); 383 if (!node) 384 return TEE_ERROR_GENERIC; 385 committed_version = !!(node->node.flags & 386 HTREE_NODE_COMMITTED_CHILD(node_id & 1)); 387 388 res = rpc_read_node(ht, node_id, committed_version, 389 &node_image); 390 if (res != TEE_SUCCESS) 391 return res; 392 393 res = get_node(ht, true, node_id, &nc); 394 if (res != TEE_SUCCESS) 395 return res; 396 nc->node = node_image; 397 node_id++; 398 } 399 400 return TEE_SUCCESS; 401 } 402 403 static TEE_Result calc_node_hash(struct htree_node *node, 404 struct tee_fs_htree_meta *meta, void *ctx, 405 uint8_t *digest) 406 { 407 TEE_Result res; 408 uint8_t *ndata = (uint8_t *)&node->node + sizeof(node->node.hash); 409 size_t nsize = sizeof(node->node) - sizeof(node->node.hash); 410 411 res = crypto_hash_init(ctx); 412 if (res != TEE_SUCCESS) 413 return res; 414 415 res = crypto_hash_update(ctx, ndata, nsize); 416 if (res != TEE_SUCCESS) 417 return res; 418 419 if (meta) { 420 res = crypto_hash_update(ctx, (void *)meta, sizeof(*meta)); 421 if (res != TEE_SUCCESS) 422 return res; 423 } 424 425 if (node->child[0]) { 426 res = crypto_hash_update(ctx, node->child[0]->node.hash, 427 sizeof(node->child[0]->node.hash)); 428 if (res != TEE_SUCCESS) 429 return res; 430 } 431 432 if (node->child[1]) { 433 res = crypto_hash_update(ctx, node->child[1]->node.hash, 434 sizeof(node->child[1]->node.hash)); 435 if (res != TEE_SUCCESS) 436 return res; 437 } 438 439 return crypto_hash_final(ctx, digest, TEE_FS_HTREE_HASH_SIZE); 440 } 441 442 static TEE_Result authenc_init(void **ctx_ret, TEE_OperationMode mode, 443 struct tee_fs_htree *ht, 444 struct tee_fs_htree_node_image *ni, 445 size_t payload_len) 446 { 447 TEE_Result res = TEE_SUCCESS; 448 const uint32_t alg = TEE_FS_HTREE_AUTH_ENC_ALG; 449 void *ctx; 450 size_t aad_len = TEE_FS_HTREE_FEK_SIZE + TEE_FS_HTREE_IV_SIZE; 451 uint8_t *iv; 452 453 if (ni) { 454 iv = ni->iv; 455 } else { 456 iv = ht->head.iv; 457 aad_len += sizeof(ht->head.counter); 458 459 /* 460 * With CFG_REE_FS_HTREE_HASH_SIZE_COMPAT, hash data passed 461 * for AAD is truncated to TEE_FS_HTREE_FEK_SIZE bytes so 462 * use the correct size aad_len computation. 463 */ 464 if (IS_ENABLED(CFG_REE_FS_HTREE_HASH_SIZE_COMPAT)) 465 aad_len += TEE_FS_HTREE_FEK_SIZE; 466 else 467 aad_len += TEE_FS_HTREE_HASH_SIZE; 468 } 469 470 if (mode == TEE_MODE_ENCRYPT) { 471 res = crypto_rng_read(iv, TEE_FS_HTREE_IV_SIZE); 472 if (res != TEE_SUCCESS) 473 return res; 474 } 475 476 res = crypto_authenc_alloc_ctx(&ctx, alg); 477 if (res != TEE_SUCCESS) 478 return res; 479 480 res = crypto_authenc_init(ctx, mode, ht->fek, TEE_FS_HTREE_FEK_SIZE, iv, 481 TEE_FS_HTREE_IV_SIZE, TEE_FS_HTREE_TAG_SIZE, 482 aad_len, payload_len); 483 if (res != TEE_SUCCESS) 484 goto err_free; 485 486 if (!ni) { 487 size_t hash_size = TEE_FS_HTREE_HASH_SIZE; 488 489 if (IS_ENABLED(CFG_REE_FS_HTREE_HASH_SIZE_COMPAT)) 490 hash_size = TEE_FS_HTREE_FEK_SIZE; 491 492 res = crypto_authenc_update_aad(ctx, mode, ht->root.node.hash, 493 hash_size); 494 if (res != TEE_SUCCESS) 495 goto err; 496 497 res = crypto_authenc_update_aad(ctx, mode, 498 (void *)&ht->head.counter, 499 sizeof(ht->head.counter)); 500 if (res != TEE_SUCCESS) 501 goto err; 502 } 503 504 res = crypto_authenc_update_aad(ctx, mode, ht->head.enc_fek, 505 TEE_FS_HTREE_FEK_SIZE); 506 if (res != TEE_SUCCESS) 507 goto err; 508 509 res = crypto_authenc_update_aad(ctx, mode, iv, TEE_FS_HTREE_IV_SIZE); 510 if (res != TEE_SUCCESS) 511 goto err; 512 513 *ctx_ret = ctx; 514 515 return TEE_SUCCESS; 516 err: 517 crypto_authenc_final(ctx); 518 err_free: 519 crypto_authenc_free_ctx(ctx); 520 return res; 521 } 522 523 static TEE_Result authenc_decrypt_final(void *ctx, const uint8_t *tag, 524 const void *crypt, size_t len, 525 void *plain) 526 { 527 TEE_Result res; 528 size_t out_size = len; 529 530 res = crypto_authenc_dec_final(ctx, crypt, len, plain, &out_size, tag, 531 TEE_FS_HTREE_TAG_SIZE); 532 crypto_authenc_final(ctx); 533 crypto_authenc_free_ctx(ctx); 534 535 if (res == TEE_SUCCESS && out_size != len) 536 return TEE_ERROR_GENERIC; 537 if (res == TEE_ERROR_MAC_INVALID) 538 return TEE_ERROR_CORRUPT_OBJECT; 539 540 return res; 541 } 542 543 static TEE_Result authenc_encrypt_final(void *ctx, uint8_t *tag, 544 const void *plain, size_t len, 545 void *crypt) 546 { 547 TEE_Result res; 548 size_t out_size = len; 549 size_t out_tag_size = TEE_FS_HTREE_TAG_SIZE; 550 551 res = crypto_authenc_enc_final(ctx, plain, len, crypt, &out_size, tag, 552 &out_tag_size); 553 crypto_authenc_final(ctx); 554 crypto_authenc_free_ctx(ctx); 555 556 if (res == TEE_SUCCESS && 557 (out_size != len || out_tag_size != TEE_FS_HTREE_TAG_SIZE)) 558 return TEE_ERROR_GENERIC; 559 560 return res; 561 } 562 563 static TEE_Result verify_root(struct tee_fs_htree *ht) 564 { 565 TEE_Result res; 566 void *ctx; 567 568 res = tee_fs_fek_crypt(ht->uuid, TEE_MODE_DECRYPT, ht->head.enc_fek, 569 sizeof(ht->fek), ht->fek); 570 if (res != TEE_SUCCESS) 571 return res; 572 573 res = authenc_init(&ctx, TEE_MODE_DECRYPT, ht, NULL, sizeof(ht->imeta)); 574 if (res != TEE_SUCCESS) 575 return res; 576 577 return authenc_decrypt_final(ctx, ht->head.tag, ht->head.imeta, 578 sizeof(ht->imeta), &ht->imeta); 579 } 580 581 static TEE_Result verify_node(struct traverse_arg *targ, 582 struct htree_node *node) 583 { 584 void *ctx = targ->arg; 585 TEE_Result res; 586 uint8_t digest[TEE_FS_HTREE_HASH_SIZE]; 587 588 if (node->parent) 589 res = calc_node_hash(node, NULL, ctx, digest); 590 else 591 res = calc_node_hash(node, &targ->ht->imeta.meta, ctx, digest); 592 if (res == TEE_SUCCESS && 593 consttime_memcmp(digest, node->node.hash, sizeof(digest))) 594 return TEE_ERROR_CORRUPT_OBJECT; 595 596 return res; 597 } 598 599 static TEE_Result verify_tree(struct tee_fs_htree *ht) 600 { 601 TEE_Result res; 602 void *ctx; 603 604 res = crypto_hash_alloc_ctx(&ctx, TEE_FS_HTREE_HASH_ALG); 605 if (res != TEE_SUCCESS) 606 return res; 607 608 res = htree_traverse_post_order(ht, verify_node, ctx); 609 crypto_hash_free_ctx(ctx); 610 611 return res; 612 } 613 614 static TEE_Result init_root_node(struct tee_fs_htree *ht) 615 { 616 TEE_Result res; 617 void *ctx; 618 619 res = crypto_hash_alloc_ctx(&ctx, TEE_FS_HTREE_HASH_ALG); 620 if (res != TEE_SUCCESS) 621 return res; 622 623 ht->root.id = 1; 624 ht->root.dirty = true; 625 626 res = calc_node_hash(&ht->root, &ht->imeta.meta, ctx, 627 ht->root.node.hash); 628 crypto_hash_free_ctx(ctx); 629 630 return res; 631 } 632 633 static TEE_Result create_and_sync(struct tee_fs_htree *ht, 634 uint8_t *hash, 635 uint32_t min_counter) 636 { 637 TEE_Result res = TEE_ERROR_GENERIC; 638 const struct tee_fs_htree_image dummy_head = { 639 .counter = min_counter, 640 }; 641 642 if (!ht) 643 return TEE_ERROR_GENERIC; 644 645 res = crypto_rng_read(ht->fek, sizeof(ht->fek)); 646 if (res != TEE_SUCCESS) 647 return res; 648 649 res = tee_fs_fek_crypt(ht->uuid, TEE_MODE_ENCRYPT, ht->fek, 650 sizeof(ht->fek), ht->head.enc_fek); 651 if (res != TEE_SUCCESS) 652 return res; 653 654 res = init_root_node(ht); 655 if (res != TEE_SUCCESS) 656 return res; 657 658 ht->dirty = true; 659 res = tee_fs_htree_sync_to_storage(&ht, hash, NULL); 660 if (res != TEE_SUCCESS) 661 return res; 662 663 return rpc_write_head(ht, 0, &dummy_head); 664 } 665 666 static bool ht_head_is_partially_done(const struct tee_fs_htree_image *head) 667 { 668 uint8_t zero_tag[TEE_FS_HTREE_TAG_SIZE] = {0}; 669 670 return head->counter == 0 && 671 !memcmp(head->tag, zero_tag, sizeof(head->tag)); 672 } 673 674 TEE_Result tee_fs_htree_open(bool create, uint8_t *hash, uint32_t min_counter, 675 const TEE_UUID *uuid, 676 const struct tee_fs_htree_storage *stor, 677 void *stor_aux, struct tee_fs_htree **ht_ret) 678 { 679 TEE_Result res; 680 struct tee_fs_htree *ht = calloc(1, sizeof(*ht)); 681 682 if (!ht) 683 return TEE_ERROR_OUT_OF_MEMORY; 684 685 ht->uuid = uuid; 686 ht->stor = stor; 687 ht->stor_aux = stor_aux; 688 689 if (create) { 690 res = create_and_sync(ht, hash, min_counter); 691 } else { 692 res = init_head_from_data(ht, hash, min_counter); 693 if (res != TEE_SUCCESS) 694 goto out; 695 696 /* 697 * If a power loss occurred during hash tree creation, the 698 * head may not have been written and counter is still 0. 699 * Re-initialze the hash tree. 700 */ 701 if (ht_head_is_partially_done(&ht->head)) { 702 res = create_and_sync(ht, hash, min_counter); 703 if (res != TEE_SUCCESS) 704 goto out; 705 } 706 707 res = verify_root(ht); 708 if (res != TEE_SUCCESS) 709 goto out; 710 711 res = init_tree_from_data(ht); 712 if (res != TEE_SUCCESS) 713 goto out; 714 715 res = verify_tree(ht); 716 } 717 out: 718 if (res == TEE_SUCCESS) 719 *ht_ret = ht; 720 else 721 tee_fs_htree_close(&ht); 722 return res; 723 } 724 725 struct tee_fs_htree_meta *tee_fs_htree_get_meta(struct tee_fs_htree *ht) 726 { 727 return &ht->imeta.meta; 728 } 729 730 void tee_fs_htree_meta_set_dirty(struct tee_fs_htree *ht) 731 { 732 ht->dirty = true; 733 ht->root.dirty = true; 734 } 735 736 static TEE_Result free_node(struct traverse_arg *targ __unused, 737 struct htree_node *node) 738 { 739 if (node->parent) 740 free(node); 741 return TEE_SUCCESS; 742 } 743 744 void tee_fs_htree_close(struct tee_fs_htree **ht) 745 { 746 if (!*ht) 747 return; 748 htree_traverse_post_order(*ht, free_node, NULL); 749 free(*ht); 750 *ht = NULL; 751 } 752 753 static TEE_Result htree_sync_node_to_storage(struct traverse_arg *targ, 754 struct htree_node *node) 755 { 756 TEE_Result res; 757 uint8_t vers; 758 struct tee_fs_htree_meta *meta = NULL; 759 760 /* 761 * The node can be dirty while the block isn't updated due to 762 * updated children, but if block is updated the node has to be 763 * dirty. 764 */ 765 assert(node->dirty >= node->block_updated); 766 767 if (!node->dirty) 768 return TEE_SUCCESS; 769 770 if (node->parent) { 771 uint32_t f = HTREE_NODE_COMMITTED_CHILD(node->id & 1); 772 773 node->parent->dirty = true; 774 node->parent->node.flags ^= f; 775 vers = !!(node->parent->node.flags & f); 776 } else { 777 /* 778 * Counter isn't updated yet, it's increased just before 779 * writing the header. 780 */ 781 vers = !(targ->ht->head.counter & 1); 782 meta = &targ->ht->imeta.meta; 783 } 784 785 res = calc_node_hash(node, meta, targ->arg, node->node.hash); 786 if (res != TEE_SUCCESS) 787 return res; 788 789 node->dirty = false; 790 node->block_updated = false; 791 792 return rpc_write_node(targ->ht, node->id, vers, &node->node); 793 } 794 795 static TEE_Result update_root(struct tee_fs_htree *ht) 796 { 797 TEE_Result res; 798 void *ctx; 799 800 ht->head.counter++; 801 802 res = authenc_init(&ctx, TEE_MODE_ENCRYPT, ht, NULL, sizeof(ht->imeta)); 803 if (res != TEE_SUCCESS) 804 return res; 805 806 return authenc_encrypt_final(ctx, ht->head.tag, &ht->imeta, 807 sizeof(ht->imeta), &ht->head.imeta); 808 } 809 810 TEE_Result tee_fs_htree_sync_to_storage(struct tee_fs_htree **ht_arg, 811 uint8_t *hash, uint32_t *counter) 812 { 813 TEE_Result res; 814 struct tee_fs_htree *ht = *ht_arg; 815 void *ctx; 816 817 if (!ht) 818 return TEE_ERROR_CORRUPT_OBJECT; 819 820 if (!ht->dirty) 821 return TEE_SUCCESS; 822 823 res = crypto_hash_alloc_ctx(&ctx, TEE_FS_HTREE_HASH_ALG); 824 if (res != TEE_SUCCESS) 825 return res; 826 827 res = htree_traverse_post_order(ht, htree_sync_node_to_storage, ctx); 828 if (res != TEE_SUCCESS) 829 goto out; 830 831 /* All the nodes are written to storage now. Time to update root. */ 832 res = update_root(ht); 833 if (res != TEE_SUCCESS) 834 goto out; 835 836 res = rpc_write_head(ht, ht->head.counter & 1, &ht->head); 837 if (res != TEE_SUCCESS) 838 goto out; 839 840 ht->dirty = false; 841 if (hash) 842 memcpy(hash, ht->root.node.hash, sizeof(ht->root.node.hash)); 843 if (counter) 844 *counter = ht->head.counter; 845 out: 846 crypto_hash_free_ctx(ctx); 847 if (res != TEE_SUCCESS) 848 tee_fs_htree_close(ht_arg); 849 return res; 850 } 851 852 static TEE_Result get_block_node(struct tee_fs_htree *ht, bool create, 853 size_t block_num, struct htree_node **node) 854 { 855 TEE_Result res; 856 struct htree_node *nd; 857 858 res = get_node(ht, create, BLOCK_NUM_TO_NODE_ID(block_num), &nd); 859 if (res == TEE_SUCCESS) 860 *node = nd; 861 862 return res; 863 } 864 865 TEE_Result tee_fs_htree_write_block(struct tee_fs_htree **ht_arg, 866 size_t block_num, const void *block) 867 { 868 struct tee_fs_htree *ht = *ht_arg; 869 TEE_Result res; 870 struct tee_fs_rpc_operation op; 871 struct htree_node *node = NULL; 872 uint8_t block_vers; 873 void *ctx; 874 void *enc_block; 875 876 if (!ht) 877 return TEE_ERROR_CORRUPT_OBJECT; 878 879 res = get_block_node(ht, true, block_num, &node); 880 if (res != TEE_SUCCESS) 881 goto out; 882 883 if (!node->block_updated) 884 node->node.flags ^= HTREE_NODE_COMMITTED_BLOCK; 885 886 block_vers = !!(node->node.flags & HTREE_NODE_COMMITTED_BLOCK); 887 res = ht->stor->rpc_write_init(ht->stor_aux, &op, 888 TEE_FS_HTREE_TYPE_BLOCK, block_num, 889 block_vers, &enc_block); 890 if (res != TEE_SUCCESS) 891 goto out; 892 893 res = authenc_init(&ctx, TEE_MODE_ENCRYPT, ht, &node->node, 894 ht->stor->block_size); 895 if (res != TEE_SUCCESS) 896 goto out; 897 res = authenc_encrypt_final(ctx, node->node.tag, block, 898 ht->stor->block_size, enc_block); 899 if (res != TEE_SUCCESS) 900 goto out; 901 902 res = ht->stor->rpc_write_final(&op); 903 if (res != TEE_SUCCESS) 904 goto out; 905 906 node->block_updated = true; 907 node->dirty = true; 908 ht->dirty = true; 909 out: 910 if (res != TEE_SUCCESS) 911 tee_fs_htree_close(ht_arg); 912 return res; 913 } 914 915 TEE_Result tee_fs_htree_read_block(struct tee_fs_htree **ht_arg, 916 size_t block_num, void *block) 917 { 918 struct tee_fs_htree *ht = *ht_arg; 919 TEE_Result res; 920 struct tee_fs_rpc_operation op; 921 struct htree_node *node; 922 uint8_t block_vers; 923 size_t len; 924 void *ctx; 925 void *enc_block; 926 927 if (!ht) 928 return TEE_ERROR_CORRUPT_OBJECT; 929 930 res = get_block_node(ht, false, block_num, &node); 931 if (res != TEE_SUCCESS) 932 goto out; 933 934 block_vers = !!(node->node.flags & HTREE_NODE_COMMITTED_BLOCK); 935 res = ht->stor->rpc_read_init(ht->stor_aux, &op, 936 TEE_FS_HTREE_TYPE_BLOCK, block_num, 937 block_vers, &enc_block); 938 if (res != TEE_SUCCESS) 939 goto out; 940 941 res = ht->stor->rpc_read_final(&op, &len); 942 if (res != TEE_SUCCESS) 943 goto out; 944 if (len != ht->stor->block_size) { 945 res = TEE_ERROR_CORRUPT_OBJECT; 946 goto out; 947 } 948 949 res = authenc_init(&ctx, TEE_MODE_DECRYPT, ht, &node->node, 950 ht->stor->block_size); 951 if (res != TEE_SUCCESS) 952 goto out; 953 954 res = authenc_decrypt_final(ctx, node->node.tag, enc_block, 955 ht->stor->block_size, block); 956 out: 957 if (res != TEE_SUCCESS) 958 tee_fs_htree_close(ht_arg); 959 return res; 960 } 961 962 TEE_Result tee_fs_htree_truncate(struct tee_fs_htree **ht_arg, size_t block_num) 963 { 964 struct tee_fs_htree *ht = *ht_arg; 965 size_t node_id = BLOCK_NUM_TO_NODE_ID(block_num); 966 struct htree_node *node; 967 968 if (!ht) 969 return TEE_ERROR_CORRUPT_OBJECT; 970 971 while (node_id < ht->imeta.max_node_id) { 972 node = find_closest_node(ht, ht->imeta.max_node_id); 973 assert(node && node->id == ht->imeta.max_node_id); 974 assert(!node->child[0] && !node->child[1]); 975 assert(node->parent); 976 assert(node->parent->child[node->id & 1] == node); 977 node->parent->child[node->id & 1] = NULL; 978 free(node); 979 ht->imeta.max_node_id--; 980 ht->dirty = true; 981 } 982 983 return TEE_SUCCESS; 984 } 985