1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Permission is hereby granted, free of charge, to any person 5 * obtaining a copy of this software and associated documentation 6 * files (the "Software"), to deal in the Software without 7 * restriction, including without limitation the rights to use, copy, 8 * modify, merge, publish, distribute, sublicense, and/or sell copies 9 * of the Software, and to permit persons to whom the Software is 10 * furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be 13 * included in all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22 * SOFTWARE. 23 */ 24 #include <common.h> 25 #include <sysmem.h> 26 #include <android_avb/avb_slot_verify.h> 27 #include <android_avb/avb_chain_partition_descriptor.h> 28 #include <android_avb/avb_cmdline.h> 29 #include <android_avb/avb_footer.h> 30 #include <android_avb/avb_hash_descriptor.h> 31 #include <android_avb/avb_hashtree_descriptor.h> 32 #include <android_avb/avb_kernel_cmdline_descriptor.h> 33 #include <android_avb/avb_sha.h> 34 #include <android_avb/avb_util.h> 35 #include <android_avb/avb_vbmeta_image.h> 36 #include <android_avb/avb_version.h> 37 38 /* Maximum number of partitions that can be loaded with avb_slot_verify(). */ 39 #define MAX_NUMBER_OF_LOADED_PARTITIONS 32 40 41 /* Maximum number of vbmeta images that can be loaded with avb_slot_verify(). */ 42 #define MAX_NUMBER_OF_VBMETA_IMAGES 32 43 44 /* Maximum size of a vbmeta image - 64 KiB. */ 45 #define VBMETA_MAX_SIZE (64 * 1024) 46 47 static AvbSlotVerifyResult initialize_persistent_digest( 48 AvbOps* ops, 49 const char* part_name, 50 const char* persistent_value_name, 51 size_t digest_size, 52 const uint8_t* initial_digest, 53 uint8_t* out_digest); 54 55 /* Helper function to see if we should continue with verification in 56 * allow_verification_error=true mode if something goes wrong. See the 57 * comments for the avb_slot_verify() function for more information. 58 */ 59 static inline bool result_should_continue(AvbSlotVerifyResult result) { 60 switch (result) { 61 case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: 62 case AVB_SLOT_VERIFY_RESULT_ERROR_IO: 63 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: 64 case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: 65 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT: 66 return false; 67 68 case AVB_SLOT_VERIFY_RESULT_OK: 69 case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: 70 case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: 71 case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: 72 return true; 73 } 74 75 return false; 76 } 77 78 static AvbSlotVerifyResult load_full_partition(AvbOps* ops, 79 const char* part_name, 80 uint64_t image_size, 81 uint8_t** out_image_buf, 82 bool* out_image_preloaded, 83 int allow_verification_error) { 84 size_t part_num_read; 85 AvbIOResult io_ret; 86 87 /* Make sure that we do not overwrite existing data. */ 88 avb_assert(*out_image_buf == NULL); 89 avb_assert(!*out_image_preloaded); 90 91 /* We are going to implicitly cast image_size from uint64_t to size_t in the 92 * following code, so we need to make sure that the cast is safe. */ 93 if (image_size != (size_t)(image_size)) { 94 avb_errorv(part_name, ": Partition size too large to load.\n", NULL); 95 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 96 } 97 98 /* Try use a preloaded one. */ 99 if (ops->get_preloaded_partition != NULL) { 100 io_ret = ops->get_preloaded_partition( 101 ops, part_name, image_size, out_image_buf, &part_num_read, 102 allow_verification_error); 103 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 104 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 105 } else if (io_ret != AVB_IO_RESULT_OK) { 106 avb_errorv(part_name, ": Error loading data from partition.\n", NULL); 107 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 108 } 109 110 if (*out_image_buf != NULL) { 111 if (part_num_read != image_size) { 112 avb_errorv(part_name, ": Read incorrect number of bytes.\n", NULL); 113 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 114 } 115 *out_image_preloaded = true; 116 } 117 } 118 119 /* Allocate and copy the partition. */ 120 if (!*out_image_preloaded) { 121 *out_image_buf = sysmem_alloc(MEM_AVB_ANDROID, image_size); 122 if (*out_image_buf == NULL) { 123 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 124 } 125 126 io_ret = ops->read_from_partition(ops, 127 part_name, 128 0 /* offset */, 129 image_size, 130 *out_image_buf, 131 &part_num_read); 132 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 133 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 134 } else if (io_ret != AVB_IO_RESULT_OK) { 135 avb_errorv(part_name, ": Error loading data from partition.\n", NULL); 136 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 137 } 138 if (part_num_read != image_size) { 139 avb_errorv(part_name, ": Read incorrect number of bytes.\n", NULL); 140 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 141 } 142 } 143 144 return AVB_SLOT_VERIFY_RESULT_OK; 145 } 146 147 /* Reads a persistent digest stored as a named persistent value corresponding to 148 * the given |part_name|. The value is returned in |out_digest| which must point 149 * to |expected_digest_size| bytes. If there is no digest stored for |part_name| 150 * it can be initialized by providing a non-NULL |initial_digest| of length 151 * |expected_digest_size|. This automatic initialization will only occur if the 152 * device is currently locked. The |initial_digest| may be NULL. 153 * 154 * Returns AVB_SLOT_VERIFY_RESULT_OK on success, otherwise returns an 155 * AVB_SLOT_VERIFY_RESULT_ERROR_* error code. 156 * 157 * If the value does not exist, is not supported, or is not populated, and 158 * |initial_digest| is NULL, returns 159 * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA. If |expected_digest_size| does 160 * not match the stored digest size, also returns 161 * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA. 162 */ 163 static AvbSlotVerifyResult read_persistent_digest(AvbOps* ops, 164 const char* part_name, 165 size_t expected_digest_size, 166 const uint8_t* initial_digest, 167 uint8_t* out_digest) { 168 char* persistent_value_name = NULL; 169 AvbIOResult io_ret = AVB_IO_RESULT_OK; 170 size_t stored_digest_size = 0; 171 172 if (ops->read_persistent_value == NULL) { 173 avb_errorv(part_name, ": Persistent values are not implemented.\n", NULL); 174 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 175 } 176 persistent_value_name = 177 avb_strdupv(AVB_NPV_PERSISTENT_DIGEST_PREFIX, part_name, NULL); 178 if (persistent_value_name == NULL) { 179 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 180 } 181 182 io_ret = ops->read_persistent_value(ops, 183 persistent_value_name, 184 expected_digest_size, 185 out_digest, 186 &stored_digest_size); 187 188 // If no such named persistent value exists and an initial digest value was 189 // given, initialize the named persistent value with the given digest. If 190 // initialized successfully, this will recurse into this function but with a 191 // NULL initial_digest. 192 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE && initial_digest) { 193 AvbSlotVerifyResult ret = 194 initialize_persistent_digest(ops, 195 part_name, 196 persistent_value_name, 197 expected_digest_size, 198 initial_digest, 199 out_digest); 200 avb_free(persistent_value_name); 201 return ret; 202 } 203 avb_free(persistent_value_name); 204 205 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 206 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 207 } else if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE) { 208 // Treat a missing persistent value as a verification error, which is 209 // ignoreable, rather than a metadata error which is not. 210 avb_errorv(part_name, ": Persistent digest does not exist.\n", NULL); 211 return AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; 212 } else if (io_ret == AVB_IO_RESULT_ERROR_INVALID_VALUE_SIZE || 213 io_ret == AVB_IO_RESULT_ERROR_INSUFFICIENT_SPACE) { 214 avb_errorv( 215 part_name, ": Persistent digest is not of expected size.\n", NULL); 216 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 217 } else if (io_ret != AVB_IO_RESULT_OK) { 218 avb_errorv(part_name, ": Error reading persistent digest.\n", NULL); 219 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 220 } else if (expected_digest_size != stored_digest_size) { 221 avb_errorv( 222 part_name, ": Persistent digest is not of expected size.\n", NULL); 223 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 224 } 225 return AVB_SLOT_VERIFY_RESULT_OK; 226 } 227 228 static AvbSlotVerifyResult initialize_persistent_digest( 229 AvbOps* ops, 230 const char* part_name, 231 const char* persistent_value_name, 232 size_t digest_size, 233 const uint8_t* initial_digest, 234 uint8_t* out_digest) { 235 AvbSlotVerifyResult ret; 236 AvbIOResult io_ret = AVB_IO_RESULT_OK; 237 bool is_device_unlocked = true; 238 239 io_ret = ops->read_is_device_unlocked(ops, &is_device_unlocked); 240 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 241 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 242 } else if (io_ret != AVB_IO_RESULT_OK) { 243 avb_error("Error getting device lock state.\n"); 244 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 245 } 246 247 if (is_device_unlocked) { 248 avb_debugv(part_name, 249 ": Digest does not exist, device unlocked so not initializing " 250 "digest.\n", 251 NULL); 252 return AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; 253 } 254 255 // Device locked; initialize digest with given initial value. 256 avb_debugv(part_name, 257 ": Digest does not exist, initializing persistent digest.\n", 258 NULL); 259 io_ret = ops->write_persistent_value( 260 ops, persistent_value_name, digest_size, initial_digest); 261 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 262 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 263 } else if (io_ret != AVB_IO_RESULT_OK) { 264 avb_errorv(part_name, ": Error initializing persistent digest.\n", NULL); 265 return AVB_SLOT_VERIFY_RESULT_ERROR_IO; 266 } 267 268 // To ensure that the digest value was written successfully - and avoid a 269 // scenario where the digest is simply 'initialized' on every verify - recurse 270 // into read_persistent_digest to read back the written value. The NULL 271 // initial_digest ensures that this will not recurse again. 272 ret = read_persistent_digest(ops, part_name, digest_size, NULL, out_digest); 273 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 274 avb_errorv(part_name, 275 ": Reading back initialized persistent digest failed!\n", 276 NULL); 277 } 278 return ret; 279 } 280 281 static AvbSlotVerifyResult load_and_verify_hash_partition( 282 AvbOps* ops, 283 const char* const* requested_partitions, 284 const char* ab_suffix, 285 bool allow_verification_error, 286 const AvbDescriptor* descriptor, 287 AvbSlotVerifyData* slot_data) { 288 AvbHashDescriptor hash_desc; 289 const uint8_t* desc_partition_name = NULL; 290 const uint8_t* desc_salt; 291 const uint8_t* desc_digest; 292 char part_name[AVB_PART_NAME_MAX_SIZE]; 293 AvbSlotVerifyResult ret; 294 AvbIOResult io_ret; 295 uint8_t* image_buf = NULL; 296 bool image_preloaded = false; 297 uint8_t* digest; 298 size_t digest_len; 299 const char* found; 300 uint64_t image_size; 301 size_t expected_digest_len = 0; 302 uint8_t expected_digest_buf[AVB_SHA512_DIGEST_SIZE]; 303 const uint8_t* expected_digest = NULL; 304 305 if (!avb_hash_descriptor_validate_and_byteswap( 306 (const AvbHashDescriptor*)descriptor, &hash_desc)) { 307 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 308 goto out; 309 } 310 311 desc_partition_name = 312 ((const uint8_t*)descriptor) + sizeof(AvbHashDescriptor); 313 desc_salt = desc_partition_name + hash_desc.partition_name_len; 314 desc_digest = desc_salt + hash_desc.salt_len; 315 316 if (!avb_validate_utf8(desc_partition_name, hash_desc.partition_name_len)) { 317 avb_error("Partition name is not valid UTF-8.\n"); 318 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 319 goto out; 320 } 321 322 /* Don't bother loading or validating unless the partition was 323 * requested in the first place. 324 */ 325 found = avb_strv_find_str(requested_partitions, 326 (const char*)desc_partition_name, 327 hash_desc.partition_name_len); 328 if (found == NULL) { 329 ret = AVB_SLOT_VERIFY_RESULT_OK; 330 goto out; 331 } 332 333 if ((hash_desc.flags & AVB_HASH_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) != 0) { 334 /* No ab_suffix, just copy the partition name as is. */ 335 if (hash_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) { 336 avb_error("Partition name does not fit.\n"); 337 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 338 goto out; 339 } 340 avb_memcpy(part_name, desc_partition_name, hash_desc.partition_name_len); 341 part_name[hash_desc.partition_name_len] = '\0'; 342 } else if (hash_desc.digest_len == 0 && avb_strlen(ab_suffix) != 0) { 343 /* No ab_suffix allowed for partitions without a digest in the descriptor 344 * because these partitions hold data unique to this device and are not 345 * updated using an A/B scheme. 346 */ 347 avb_error("Cannot use A/B with a persistent digest.\n"); 348 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 349 goto out; 350 } else { 351 /* Add ab_suffix to the partition name. */ 352 if (!avb_str_concat(part_name, 353 sizeof part_name, 354 (const char*)desc_partition_name, 355 hash_desc.partition_name_len, 356 ab_suffix, 357 avb_strlen(ab_suffix))) { 358 avb_error("Partition name and suffix does not fit.\n"); 359 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 360 goto out; 361 } 362 } 363 364 /* If we're allowing verification errors then hash_desc.image_size 365 * may no longer match what's in the partition... so in this case 366 * just load the entire partition. 367 * 368 * For example, this can happen if a developer does 'fastboot flash 369 * boot /path/to/new/and/bigger/boot.img'. We want this to work 370 * since it's such a common workflow. 371 */ 372 image_size = hash_desc.image_size; 373 if (allow_verification_error) { 374 io_ret = ops->get_size_of_partition(ops, part_name, &image_size); 375 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 376 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 377 goto out; 378 } else if (io_ret != AVB_IO_RESULT_OK) { 379 avb_errorv(part_name, ": Error determining partition size.\n", NULL); 380 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 381 goto out; 382 } 383 avb_debugv(part_name, ": Loading entire partition.\n", NULL); 384 } 385 386 ret = load_full_partition( 387 ops, part_name, image_size, &image_buf, &image_preloaded, 388 allow_verification_error); 389 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 390 goto out; 391 } 392 // Although only one of the type might be used, we have to defined the 393 // structure here so that they would live outside the 'if/else' scope to be 394 // used later. 395 AvbSHA256Ctx sha256_ctx; 396 AvbSHA512Ctx sha512_ctx; 397 size_t image_size_to_hash = hash_desc.image_size; 398 // If we allow verification error and the whole partition is smaller than 399 // image size in hash descriptor, we just hash the whole partition. 400 if (image_size_to_hash > image_size) { 401 image_size_to_hash = image_size; 402 } 403 if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha256") == 0) { 404 avb_sha256_init(&sha256_ctx); 405 avb_sha256_update(&sha256_ctx, desc_salt, hash_desc.salt_len); 406 avb_sha256_update(&sha256_ctx, image_buf, image_size_to_hash); 407 digest = avb_sha256_final(&sha256_ctx); 408 digest_len = AVB_SHA256_DIGEST_SIZE; 409 } else if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha512") == 0) { 410 avb_sha512_init(&sha512_ctx); 411 avb_sha512_update(&sha512_ctx, desc_salt, hash_desc.salt_len); 412 avb_sha512_update(&sha512_ctx, image_buf, image_size_to_hash); 413 digest = avb_sha512_final(&sha512_ctx); 414 digest_len = AVB_SHA512_DIGEST_SIZE; 415 } else { 416 avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); 417 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 418 goto out; 419 } 420 421 if (hash_desc.digest_len == 0) { 422 /* Expect a match to a persistent digest. */ 423 avb_debugv(part_name, ": No digest, using persistent digest.\n", NULL); 424 expected_digest_len = digest_len; 425 expected_digest = expected_digest_buf; 426 avb_assert(expected_digest_len <= sizeof(expected_digest_buf)); 427 /* Pass |digest| as the |initial_digest| so devices not yet initialized get 428 * initialized to the current partition digest. 429 */ 430 ret = read_persistent_digest( 431 ops, part_name, digest_len, digest, expected_digest_buf); 432 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 433 goto out; 434 } 435 } else { 436 /* Expect a match to the digest in the descriptor. */ 437 expected_digest_len = hash_desc.digest_len; 438 expected_digest = desc_digest; 439 } 440 441 if (digest_len != expected_digest_len) { 442 avb_errorv( 443 part_name, ": Digest in descriptor not of expected size.\n", NULL); 444 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 445 goto out; 446 } 447 448 if (avb_safe_memcmp(digest, expected_digest, digest_len) != 0) { 449 avb_errorv(part_name, 450 ": Hash of data does not match digest in descriptor.\n", 451 NULL); 452 ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; 453 goto out; 454 } 455 456 ret = AVB_SLOT_VERIFY_RESULT_OK; 457 458 out: 459 460 /* If it worked and something was loaded, copy to slot_data. */ 461 if ((ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) && 462 image_buf != NULL) { 463 AvbPartitionData* loaded_partition; 464 if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { 465 avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); 466 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 467 goto fail; 468 } 469 loaded_partition = 470 &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; 471 loaded_partition->partition_name = avb_strdup(found); 472 loaded_partition->data_size = image_size; 473 loaded_partition->data = image_buf; 474 loaded_partition->preloaded = image_preloaded; 475 image_buf = NULL; 476 } 477 478 fail: 479 if (image_buf != NULL && !image_preloaded) { 480 sysmem_free((phys_addr_t)image_buf); 481 } 482 return ret; 483 } 484 485 static AvbSlotVerifyResult load_requested_partitions( 486 AvbOps* ops, 487 const char* const* requested_partitions, 488 const char* ab_suffix, 489 AvbSlotVerifyData* slot_data) { 490 AvbSlotVerifyResult ret; 491 uint8_t* image_buf = NULL; 492 bool image_preloaded = false; 493 size_t n; 494 495 for (n = 0; requested_partitions[n] != NULL; n++) { 496 char part_name[AVB_PART_NAME_MAX_SIZE]; 497 AvbIOResult io_ret; 498 uint64_t image_size; 499 AvbPartitionData* loaded_partition; 500 501 if (!avb_str_concat(part_name, 502 sizeof part_name, 503 requested_partitions[n], 504 avb_strlen(requested_partitions[n]), 505 ab_suffix, 506 avb_strlen(ab_suffix))) { 507 avb_error("Partition name and suffix does not fit.\n"); 508 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 509 goto out; 510 } 511 512 io_ret = ops->get_size_of_partition(ops, part_name, &image_size); 513 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 514 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 515 goto out; 516 } else if (io_ret != AVB_IO_RESULT_OK) { 517 avb_errorv(part_name, ": Error determining partition size.\n", NULL); 518 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 519 goto out; 520 } 521 avb_debugv(part_name, ": Loading entire partition.\n", NULL); 522 523 ret = load_full_partition( 524 ops, part_name, image_size, &image_buf, &image_preloaded, 1); 525 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 526 goto out; 527 } 528 529 /* Move to slot_data. */ 530 if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { 531 avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); 532 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 533 goto out; 534 } 535 loaded_partition = 536 &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; 537 loaded_partition->partition_name = avb_strdup(requested_partitions[n]); 538 if (loaded_partition->partition_name == NULL) { 539 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 540 goto out; 541 } 542 loaded_partition->data_size = image_size; 543 loaded_partition->data = image_buf; /* Transferring the owner. */ 544 loaded_partition->preloaded = image_preloaded; 545 image_buf = NULL; 546 image_preloaded = false; 547 } 548 549 ret = AVB_SLOT_VERIFY_RESULT_OK; 550 551 out: 552 /* Free the current buffer if any. */ 553 if (image_buf != NULL && !image_preloaded) { 554 sysmem_free((phys_addr_t)image_buf); 555 } 556 /* Buffers that are already saved in slot_data will be handled by the caller 557 * even on failure. */ 558 return ret; 559 } 560 561 static AvbSlotVerifyResult load_and_verify_vbmeta( 562 AvbOps* ops, 563 const char* const* requested_partitions, 564 const char* ab_suffix, 565 AvbSlotVerifyFlags flags, 566 bool allow_verification_error, 567 AvbVBMetaImageFlags toplevel_vbmeta_flags, 568 int rollback_index_location, 569 const char* partition_name, 570 size_t partition_name_len, 571 const uint8_t* expected_public_key, 572 size_t expected_public_key_length, 573 AvbSlotVerifyData* slot_data, 574 AvbAlgorithmType* out_algorithm_type, 575 AvbCmdlineSubstList* out_additional_cmdline_subst) { 576 char full_partition_name[AVB_PART_NAME_MAX_SIZE]; 577 AvbSlotVerifyResult ret; 578 AvbIOResult io_ret; 579 uint64_t vbmeta_offset; 580 size_t vbmeta_size; 581 uint8_t* vbmeta_buf = NULL; 582 size_t vbmeta_num_read; 583 AvbVBMetaVerifyResult vbmeta_ret; 584 const uint8_t* pk_data; 585 size_t pk_len; 586 AvbVBMetaImageHeader vbmeta_header; 587 uint64_t stored_rollback_index; 588 const AvbDescriptor** descriptors = NULL; 589 size_t num_descriptors; 590 size_t n; 591 bool is_main_vbmeta; 592 bool look_for_vbmeta_footer; 593 AvbVBMetaData* vbmeta_image_data = NULL; 594 595 ret = AVB_SLOT_VERIFY_RESULT_OK; 596 597 avb_assert(slot_data != NULL); 598 599 /* Since we allow top-level vbmeta in 'boot', use 600 * rollback_index_location to determine whether we're the main 601 * vbmeta struct. 602 */ 603 is_main_vbmeta = false; 604 if (rollback_index_location == 0) { 605 if ((flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) == 0) { 606 is_main_vbmeta = true; 607 } 608 } 609 610 /* Don't use footers for vbmeta partitions ('vbmeta' or 611 * 'vbmeta_<partition_name>'). 612 */ 613 look_for_vbmeta_footer = true; 614 if (avb_strncmp(partition_name, "vbmeta", avb_strlen("vbmeta")) == 0) { 615 look_for_vbmeta_footer = false; 616 } 617 618 if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) { 619 avb_error("Partition name is not valid UTF-8.\n"); 620 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 621 goto out; 622 } 623 624 /* Construct full partition name e.g. system_a. */ 625 if (!avb_str_concat(full_partition_name, 626 sizeof full_partition_name, 627 partition_name, 628 partition_name_len, 629 ab_suffix, 630 avb_strlen(ab_suffix))) { 631 avb_error("Partition name and suffix does not fit.\n"); 632 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 633 goto out; 634 } 635 636 /* If we're loading from the main vbmeta partition, the vbmeta struct is in 637 * the beginning. Otherwise we may have to locate it via a footer... if no 638 * footer is found, we look in the beginning to support e.g. vbmeta_<org> 639 * partitions holding data for e.g. super partitions (b/80195851 for 640 * rationale). 641 */ 642 vbmeta_offset = 0; 643 vbmeta_size = VBMETA_MAX_SIZE; 644 if (look_for_vbmeta_footer) { 645 uint8_t footer_buf[AVB_FOOTER_SIZE]; 646 size_t footer_num_read; 647 AvbFooter footer; 648 649 io_ret = ops->read_from_partition(ops, 650 full_partition_name, 651 -AVB_FOOTER_SIZE, 652 AVB_FOOTER_SIZE, 653 footer_buf, 654 &footer_num_read); 655 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 656 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 657 goto out; 658 } else if (io_ret != AVB_IO_RESULT_OK) { 659 avb_errorv(full_partition_name, ": Error loading footer.\n", NULL); 660 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 661 goto out; 662 } 663 avb_assert(footer_num_read == AVB_FOOTER_SIZE); 664 665 if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf, 666 &footer)) { 667 avb_debugv(full_partition_name, ": No footer detected.\n", NULL); 668 } else { 669 /* Basic footer sanity check since the data is untrusted. */ 670 if (footer.vbmeta_size > VBMETA_MAX_SIZE) { 671 avb_errorv( 672 full_partition_name, ": Invalid vbmeta size in footer.\n", NULL); 673 } else { 674 vbmeta_offset = footer.vbmeta_offset; 675 vbmeta_size = footer.vbmeta_size; 676 } 677 } 678 } 679 680 vbmeta_buf = avb_malloc(vbmeta_size); 681 if (vbmeta_buf == NULL) { 682 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 683 goto out; 684 } 685 686 if (vbmeta_offset != 0) { 687 avb_debugv("Loading vbmeta struct in footer from partition '", 688 full_partition_name, 689 "'.\n", 690 NULL); 691 } else { 692 avb_debugv("Loading vbmeta struct from partition '", 693 full_partition_name, 694 "'.\n", 695 NULL); 696 } 697 698 io_ret = ops->read_from_partition(ops, 699 full_partition_name, 700 vbmeta_offset, 701 vbmeta_size, 702 vbmeta_buf, 703 &vbmeta_num_read); 704 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 705 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 706 goto out; 707 } else if (io_ret != AVB_IO_RESULT_OK) { 708 /* If we're looking for 'vbmeta' but there is no such partition, 709 * go try to get it from the boot partition instead. 710 */ 711 if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION && 712 !look_for_vbmeta_footer) { 713 avb_debugv(full_partition_name, 714 ": No such partition. Trying 'boot' instead.\n", 715 NULL); 716 ret = load_and_verify_vbmeta(ops, 717 requested_partitions, 718 ab_suffix, 719 flags, 720 allow_verification_error, 721 0 /* toplevel_vbmeta_flags */, 722 0 /* rollback_index_location */, 723 "boot", 724 avb_strlen("boot"), 725 NULL /* expected_public_key */, 726 0 /* expected_public_key_length */, 727 slot_data, 728 out_algorithm_type, 729 out_additional_cmdline_subst); 730 goto out; 731 } else { 732 avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL); 733 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 734 goto out; 735 } 736 } 737 avb_assert(vbmeta_num_read <= vbmeta_size); 738 739 /* Check if the image is properly signed and get the public key used 740 * to sign the image. 741 */ 742 vbmeta_ret = 743 avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len); 744 switch (vbmeta_ret) { 745 case AVB_VBMETA_VERIFY_RESULT_OK: 746 avb_assert(pk_data != NULL && pk_len > 0); 747 break; 748 749 case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED: 750 case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH: 751 case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH: 752 ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; 753 avb_errorv(full_partition_name, 754 ": Error verifying vbmeta image: ", 755 avb_vbmeta_verify_result_to_string(vbmeta_ret), 756 "\n", 757 NULL); 758 if (!allow_verification_error) { 759 goto out; 760 } 761 break; 762 763 case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER: 764 /* No way to continue this case. */ 765 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 766 avb_errorv(full_partition_name, 767 ": Error verifying vbmeta image: invalid vbmeta header\n", 768 NULL); 769 goto out; 770 771 case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION: 772 /* No way to continue this case. */ 773 ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION; 774 avb_errorv(full_partition_name, 775 ": Error verifying vbmeta image: unsupported AVB version\n", 776 NULL); 777 goto out; 778 } 779 780 /* Byteswap the header. */ 781 avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf, 782 &vbmeta_header); 783 784 /* If we're the toplevel, assign flags so they'll be passed down. */ 785 if (is_main_vbmeta) { 786 toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags; 787 } else { 788 if (vbmeta_header.flags != 0) { 789 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 790 avb_errorv(full_partition_name, 791 ": chained vbmeta image has non-zero flags\n", 792 NULL); 793 goto out; 794 } 795 } 796 797 uint32_t rollback_index_location_to_use = rollback_index_location; 798 799 /* Check if key used to make signature matches what is expected. */ 800 if (pk_data != NULL) { 801 if (expected_public_key != NULL) { 802 avb_assert(!is_main_vbmeta); 803 if (expected_public_key_length != pk_len || 804 avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) { 805 avb_errorv(full_partition_name, 806 ": Public key used to sign data does not match key in chain " 807 "partition descriptor.\n", 808 NULL); 809 ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; 810 if (!allow_verification_error) { 811 goto out; 812 } 813 } 814 } else { 815 bool key_is_trusted = false; 816 const uint8_t* pk_metadata = NULL; 817 size_t pk_metadata_len = 0; 818 819 if (vbmeta_header.public_key_metadata_size > 0) { 820 pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) + 821 vbmeta_header.authentication_data_block_size + 822 vbmeta_header.public_key_metadata_offset; 823 pk_metadata_len = vbmeta_header.public_key_metadata_size; 824 } 825 826 // If we're not using a vbmeta partition, need to use another AvbOps... 827 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) { 828 io_ret = ops->validate_public_key_for_partition( 829 ops, 830 full_partition_name, 831 pk_data, 832 pk_len, 833 pk_metadata, 834 pk_metadata_len, 835 &key_is_trusted, 836 &rollback_index_location_to_use); 837 } else { 838 avb_assert(is_main_vbmeta); 839 io_ret = ops->validate_vbmeta_public_key(ops, 840 pk_data, 841 pk_len, 842 pk_metadata, 843 pk_metadata_len, 844 &key_is_trusted); 845 } 846 847 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 848 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 849 goto out; 850 } else if (io_ret != AVB_IO_RESULT_OK) { 851 avb_errorv(full_partition_name, 852 ": Error while checking public key used to sign data.\n", 853 NULL); 854 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 855 goto out; 856 } 857 if (!key_is_trusted) { 858 avb_errorv(full_partition_name, 859 ": Public key used to sign data rejected.\n", 860 NULL); 861 ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; 862 if (!allow_verification_error) { 863 goto out; 864 } 865 } 866 } 867 } 868 869 /* Check rollback index. */ 870 io_ret = ops->read_rollback_index( 871 ops, rollback_index_location_to_use, &stored_rollback_index); 872 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 873 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 874 goto out; 875 } else if (io_ret != AVB_IO_RESULT_OK) { 876 avb_errorv(full_partition_name, 877 ": Error getting rollback index for location.\n", 878 NULL); 879 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 880 goto out; 881 } 882 if (vbmeta_header.rollback_index < stored_rollback_index) { 883 avb_errorv( 884 full_partition_name, 885 ": Image rollback index is less than the stored rollback index.\n", 886 NULL); 887 ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX; 888 if (!allow_verification_error) { 889 goto out; 890 } 891 } 892 893 /* Copy vbmeta to vbmeta_images before recursing. */ 894 if (is_main_vbmeta) { 895 avb_assert(slot_data->num_vbmeta_images == 0); 896 } else { 897 if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) { 898 avb_assert(slot_data->num_vbmeta_images > 0); 899 } 900 } 901 if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) { 902 avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL); 903 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 904 goto out; 905 } 906 vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++]; 907 vbmeta_image_data->partition_name = avb_strdup(partition_name); 908 vbmeta_image_data->vbmeta_data = vbmeta_buf; 909 /* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long 910 * and this includes data past the end of the image. Pass the 911 * actual size of the vbmeta image. Also, no need to use 912 * avb_safe_add() since the header has already been verified. 913 */ 914 vbmeta_image_data->vbmeta_size = 915 sizeof(AvbVBMetaImageHeader) + 916 vbmeta_header.authentication_data_block_size + 917 vbmeta_header.auxiliary_data_block_size; 918 vbmeta_image_data->verify_result = vbmeta_ret; 919 920 /* If verification has been disabled by setting a bit in the image, 921 * we're done... except that we need to load the entirety of the 922 * requested partitions. 923 */ 924 if (vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) { 925 AvbSlotVerifyResult sub_ret; 926 avb_debugv( 927 full_partition_name, ": VERIFICATION_DISABLED bit is set.\n", NULL); 928 /* If load_requested_partitions() fail it is always a fatal 929 * failure (e.g. ERROR_INVALID_ARGUMENT, ERROR_OOM, etc.) rather 930 * than recoverable (e.g. one where result_should_continue() 931 * returns true) and we want to convey that error. 932 */ 933 sub_ret = load_requested_partitions( 934 ops, requested_partitions, ab_suffix, slot_data); 935 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 936 ret = sub_ret; 937 } 938 goto out; 939 } 940 941 /* Now go through all descriptors and take the appropriate action: 942 * 943 * - hash descriptor: Load data from partition, calculate hash, and 944 * checks that it matches what's in the hash descriptor. 945 * 946 * - hashtree descriptor: Do nothing since verification happens 947 * on-the-fly from within the OS. (Unless the descriptor uses a 948 * persistent digest, in which case we need to find it). 949 * 950 * - chained partition descriptor: Load the footer, load the vbmeta 951 * image, verify vbmeta image (includes rollback checks, hash 952 * checks, bail on chained partitions). 953 */ 954 descriptors = 955 avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors); 956 for (n = 0; n < num_descriptors; n++) { 957 AvbDescriptor desc; 958 959 if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) { 960 avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL); 961 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 962 goto out; 963 } 964 965 switch (desc.tag) { 966 case AVB_DESCRIPTOR_TAG_HASH: { 967 AvbSlotVerifyResult sub_ret; 968 sub_ret = load_and_verify_hash_partition(ops, 969 requested_partitions, 970 ab_suffix, 971 allow_verification_error, 972 descriptors[n], 973 slot_data); 974 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 975 ret = sub_ret; 976 if (!allow_verification_error || !result_should_continue(ret)) { 977 goto out; 978 } 979 } 980 } break; 981 982 case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: { 983 AvbSlotVerifyResult sub_ret; 984 AvbChainPartitionDescriptor chain_desc; 985 const uint8_t* chain_partition_name; 986 const uint8_t* chain_public_key; 987 988 /* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */ 989 if (!is_main_vbmeta) { 990 avb_errorv(full_partition_name, 991 ": Encountered chain descriptor not in main image.\n", 992 NULL); 993 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 994 goto out; 995 } 996 997 if (!avb_chain_partition_descriptor_validate_and_byteswap( 998 (AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) { 999 avb_errorv(full_partition_name, 1000 ": Chain partition descriptor is invalid.\n", 1001 NULL); 1002 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1003 goto out; 1004 } 1005 1006 if (chain_desc.rollback_index_location == 0) { 1007 avb_errorv(full_partition_name, 1008 ": Chain partition has invalid " 1009 "rollback_index_location field.\n", 1010 NULL); 1011 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1012 goto out; 1013 } 1014 1015 chain_partition_name = ((const uint8_t*)descriptors[n]) + 1016 sizeof(AvbChainPartitionDescriptor); 1017 chain_public_key = chain_partition_name + chain_desc.partition_name_len; 1018 1019 sub_ret = 1020 load_and_verify_vbmeta(ops, 1021 requested_partitions, 1022 ab_suffix, 1023 flags, 1024 allow_verification_error, 1025 toplevel_vbmeta_flags, 1026 chain_desc.rollback_index_location, 1027 (const char*)chain_partition_name, 1028 chain_desc.partition_name_len, 1029 chain_public_key, 1030 chain_desc.public_key_len, 1031 slot_data, 1032 NULL, /* out_algorithm_type */ 1033 NULL /* out_additional_cmdline_subst */); 1034 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 1035 ret = sub_ret; 1036 if (!result_should_continue(ret)) { 1037 goto out; 1038 } 1039 } 1040 } break; 1041 1042 case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: { 1043 const uint8_t* kernel_cmdline; 1044 AvbKernelCmdlineDescriptor kernel_cmdline_desc; 1045 bool apply_cmdline; 1046 1047 if (!avb_kernel_cmdline_descriptor_validate_and_byteswap( 1048 (AvbKernelCmdlineDescriptor*)descriptors[n], 1049 &kernel_cmdline_desc)) { 1050 avb_errorv(full_partition_name, 1051 ": Kernel cmdline descriptor is invalid.\n", 1052 NULL); 1053 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1054 goto out; 1055 } 1056 1057 kernel_cmdline = ((const uint8_t*)descriptors[n]) + 1058 sizeof(AvbKernelCmdlineDescriptor); 1059 1060 if (!avb_validate_utf8(kernel_cmdline, 1061 kernel_cmdline_desc.kernel_cmdline_length)) { 1062 avb_errorv(full_partition_name, 1063 ": Kernel cmdline is not valid UTF-8.\n", 1064 NULL); 1065 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1066 goto out; 1067 } 1068 1069 /* Compare the flags for top-level VBMeta struct with flags in 1070 * the command-line descriptor so command-line snippets only 1071 * intended for a certain mode (dm-verity enabled/disabled) 1072 * are skipped if applicable. 1073 */ 1074 apply_cmdline = true; 1075 if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) { 1076 if (kernel_cmdline_desc.flags & 1077 AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) { 1078 apply_cmdline = false; 1079 } 1080 } else { 1081 if (kernel_cmdline_desc.flags & 1082 AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) { 1083 apply_cmdline = false; 1084 } 1085 } 1086 1087 if (apply_cmdline) { 1088 if (slot_data->cmdline == NULL) { 1089 slot_data->cmdline = 1090 avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1); 1091 if (slot_data->cmdline == NULL) { 1092 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1093 goto out; 1094 } 1095 avb_memcpy(slot_data->cmdline, 1096 kernel_cmdline, 1097 kernel_cmdline_desc.kernel_cmdline_length); 1098 } else { 1099 /* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */ 1100 size_t orig_size = avb_strlen(slot_data->cmdline); 1101 size_t new_size = 1102 orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1; 1103 char* new_cmdline = avb_calloc(new_size); 1104 if (new_cmdline == NULL) { 1105 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1106 goto out; 1107 } 1108 avb_memcpy(new_cmdline, slot_data->cmdline, orig_size); 1109 new_cmdline[orig_size] = ' '; 1110 avb_memcpy(new_cmdline + orig_size + 1, 1111 kernel_cmdline, 1112 kernel_cmdline_desc.kernel_cmdline_length); 1113 avb_free(slot_data->cmdline); 1114 slot_data->cmdline = new_cmdline; 1115 } 1116 } 1117 } break; 1118 1119 case AVB_DESCRIPTOR_TAG_HASHTREE: { 1120 AvbHashtreeDescriptor hashtree_desc; 1121 1122 if (!avb_hashtree_descriptor_validate_and_byteswap( 1123 (AvbHashtreeDescriptor*)descriptors[n], &hashtree_desc)) { 1124 avb_errorv( 1125 full_partition_name, ": Hashtree descriptor is invalid.\n", NULL); 1126 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1127 goto out; 1128 } 1129 1130 /* We only need to continue when there is no digest in the descriptor. 1131 * This is because the only processing here is to find the digest and 1132 * make it available on the kernel command line. 1133 */ 1134 if (hashtree_desc.root_digest_len == 0) { 1135 char part_name[AVB_PART_NAME_MAX_SIZE]; 1136 size_t digest_len = 0; 1137 uint8_t digest_buf[AVB_SHA512_DIGEST_SIZE]; 1138 const uint8_t* desc_partition_name = 1139 ((const uint8_t*)descriptors[n]) + sizeof(AvbHashtreeDescriptor); 1140 1141 if (!avb_validate_utf8(desc_partition_name, 1142 hashtree_desc.partition_name_len)) { 1143 avb_error("Partition name is not valid UTF-8.\n"); 1144 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1145 goto out; 1146 } 1147 1148 /* No ab_suffix for partitions without a digest in the descriptor 1149 * because these partitions hold data unique to this device and are 1150 * not updated using an A/B scheme. 1151 */ 1152 if ((hashtree_desc.flags & 1153 AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) == 0 && 1154 avb_strlen(ab_suffix) != 0) { 1155 avb_error("Cannot use A/B with a persistent root digest.\n"); 1156 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1157 goto out; 1158 } 1159 if (hashtree_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) { 1160 avb_error("Partition name does not fit.\n"); 1161 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1162 goto out; 1163 } 1164 avb_memcpy( 1165 part_name, desc_partition_name, hashtree_desc.partition_name_len); 1166 part_name[hashtree_desc.partition_name_len] = '\0'; 1167 1168 /* Determine the expected digest size from the hash algorithm. */ 1169 if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, "sha1") == 1170 0) { 1171 digest_len = AVB_SHA1_DIGEST_SIZE; 1172 } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, 1173 "sha256") == 0) { 1174 digest_len = AVB_SHA256_DIGEST_SIZE; 1175 } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, 1176 "sha512") == 0) { 1177 digest_len = AVB_SHA512_DIGEST_SIZE; 1178 } else { 1179 avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); 1180 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1181 goto out; 1182 } 1183 1184 ret = read_persistent_digest(ops, 1185 part_name, 1186 digest_len, 1187 NULL /* initial_digest */, 1188 digest_buf); 1189 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 1190 goto out; 1191 } 1192 1193 if (out_additional_cmdline_subst) { 1194 ret = 1195 avb_add_root_digest_substitution(part_name, 1196 digest_buf, 1197 digest_len, 1198 out_additional_cmdline_subst); 1199 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 1200 goto out; 1201 } 1202 } 1203 } 1204 } break; 1205 1206 case AVB_DESCRIPTOR_TAG_PROPERTY: 1207 /* Do nothing. */ 1208 break; 1209 } 1210 } 1211 1212 if (rollback_index_location < 0 || 1213 rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) { 1214 avb_errorv( 1215 full_partition_name, ": Invalid rollback_index_location.\n", NULL); 1216 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1217 goto out; 1218 } 1219 1220 slot_data->rollback_indexes[rollback_index_location] = 1221 vbmeta_header.rollback_index; 1222 1223 if (out_algorithm_type != NULL) { 1224 *out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type; 1225 } 1226 1227 out: 1228 /* If |vbmeta_image_data| isn't NULL it means that it adopted 1229 * |vbmeta_buf| so in that case don't free it here. 1230 */ 1231 if (vbmeta_image_data == NULL) { 1232 if (vbmeta_buf != NULL) { 1233 avb_free(vbmeta_buf); 1234 } 1235 } 1236 if (descriptors != NULL) { 1237 avb_free(descriptors); 1238 } 1239 return ret; 1240 } 1241 1242 static AvbIOResult avb_manage_hashtree_error_mode( 1243 AvbOps* ops, 1244 AvbSlotVerifyFlags flags, 1245 AvbSlotVerifyData* data, 1246 AvbHashtreeErrorMode* out_hashtree_error_mode) { 1247 AvbHashtreeErrorMode ret = AVB_HASHTREE_ERROR_MODE_RESTART; 1248 AvbIOResult io_ret = AVB_IO_RESULT_OK; 1249 uint8_t vbmeta_digest_sha256[AVB_SHA256_DIGEST_SIZE]; 1250 uint8_t stored_vbmeta_digest_sha256[AVB_SHA256_DIGEST_SIZE]; 1251 size_t num_bytes_read; 1252 1253 avb_assert(out_hashtree_error_mode != NULL); 1254 avb_assert(ops->read_persistent_value != NULL); 1255 avb_assert(ops->write_persistent_value != NULL); 1256 1257 // If we're rebooting because of dm-verity corruption, make a note of 1258 // the vbmeta hash so we can stay in 'eio' mode until things change. 1259 if (flags & AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION) { 1260 avb_debug( 1261 "Rebooting because of dm-verity corruption - " 1262 "recording OS instance and using 'eio' mode.\n"); 1263 avb_slot_verify_data_calculate_vbmeta_digest( 1264 data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest_sha256); 1265 io_ret = ops->write_persistent_value(ops, 1266 AVB_NPV_MANAGED_VERITY_MODE, 1267 AVB_SHA256_DIGEST_SIZE, 1268 vbmeta_digest_sha256); 1269 if (io_ret != AVB_IO_RESULT_OK) { 1270 avb_error("Error writing to " AVB_NPV_MANAGED_VERITY_MODE ".\n"); 1271 goto out; 1272 } 1273 ret = AVB_HASHTREE_ERROR_MODE_EIO; 1274 io_ret = AVB_IO_RESULT_OK; 1275 goto out; 1276 } 1277 1278 // See if we're in 'eio' mode. 1279 io_ret = ops->read_persistent_value(ops, 1280 AVB_NPV_MANAGED_VERITY_MODE, 1281 AVB_SHA256_DIGEST_SIZE, 1282 stored_vbmeta_digest_sha256, 1283 &num_bytes_read); 1284 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE || 1285 (io_ret == AVB_IO_RESULT_OK && num_bytes_read == 0)) { 1286 // This is the usual case ('eio' mode not set). 1287 avb_debug("No dm-verity corruption - using in 'restart' mode.\n"); 1288 ret = AVB_HASHTREE_ERROR_MODE_RESTART; 1289 io_ret = AVB_IO_RESULT_OK; 1290 goto out; 1291 } else if (io_ret != AVB_IO_RESULT_OK) { 1292 avb_error("Error reading from " AVB_NPV_MANAGED_VERITY_MODE ".\n"); 1293 goto out; 1294 } 1295 if (num_bytes_read != AVB_SHA256_DIGEST_SIZE) { 1296 avb_error( 1297 "Unexpected number of bytes read from " AVB_NPV_MANAGED_VERITY_MODE 1298 ".\n"); 1299 io_ret = AVB_IO_RESULT_ERROR_IO; 1300 goto out; 1301 } 1302 1303 // OK, so we're currently in 'eio' mode and the vbmeta digest of the OS 1304 // that caused this is in |stored_vbmeta_digest_sha256| ... now see if 1305 // the OS we're dealing with now is the same. 1306 avb_slot_verify_data_calculate_vbmeta_digest( 1307 data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest_sha256); 1308 if (avb_memcmp(vbmeta_digest_sha256, 1309 stored_vbmeta_digest_sha256, 1310 AVB_SHA256_DIGEST_SIZE) == 0) { 1311 // It's the same so we're still in 'eio' mode. 1312 avb_debug("Same OS instance detected - staying in 'eio' mode.\n"); 1313 ret = AVB_HASHTREE_ERROR_MODE_EIO; 1314 io_ret = AVB_IO_RESULT_OK; 1315 } else { 1316 // It did change! 1317 avb_debug( 1318 "New OS instance detected - changing from 'eio' to 'restart' mode.\n"); 1319 io_ret = 1320 ops->write_persistent_value(ops, 1321 AVB_NPV_MANAGED_VERITY_MODE, 1322 0, // This clears the persistent property. 1323 vbmeta_digest_sha256); 1324 if (io_ret != AVB_IO_RESULT_OK) { 1325 avb_error("Error clearing " AVB_NPV_MANAGED_VERITY_MODE ".\n"); 1326 goto out; 1327 } 1328 ret = AVB_HASHTREE_ERROR_MODE_RESTART; 1329 io_ret = AVB_IO_RESULT_OK; 1330 } 1331 1332 out: 1333 *out_hashtree_error_mode = ret; 1334 return io_ret; 1335 } 1336 1337 static bool has_system_partition(AvbOps* ops, const char* ab_suffix) { 1338 char part_name[AVB_PART_NAME_MAX_SIZE]; 1339 char* system_part_name = "system"; 1340 char guid_buf[37]; 1341 AvbIOResult io_ret; 1342 1343 if (!avb_str_concat(part_name, 1344 sizeof part_name, 1345 system_part_name, 1346 avb_strlen(system_part_name), 1347 ab_suffix, 1348 avb_strlen(ab_suffix))) { 1349 avb_error("System partition name and suffix does not fit.\n"); 1350 return false; 1351 } 1352 1353 io_ret = ops->get_unique_guid_for_partition( 1354 ops, part_name, guid_buf, sizeof guid_buf); 1355 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION) { 1356 avb_debug("No system partition.\n"); 1357 return false; 1358 } else if (io_ret != AVB_IO_RESULT_OK) { 1359 avb_error("Error getting unique GUID for system partition.\n"); 1360 return false; 1361 } 1362 1363 return true; 1364 } 1365 1366 AvbSlotVerifyResult avb_slot_verify(AvbOps* ops, 1367 const char* const* requested_partitions, 1368 const char* ab_suffix, 1369 AvbSlotVerifyFlags flags, 1370 AvbHashtreeErrorMode hashtree_error_mode, 1371 AvbSlotVerifyData** out_data) { 1372 AvbSlotVerifyResult ret = 0; 1373 AvbSlotVerifyData* slot_data = NULL; 1374 AvbAlgorithmType algorithm_type = AVB_ALGORITHM_TYPE_NONE; 1375 bool using_boot_for_vbmeta = false; 1376 AvbVBMetaImageHeader toplevel_vbmeta; 1377 bool allow_verification_error = 1378 (flags & AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR); 1379 AvbCmdlineSubstList* additional_cmdline_subst = NULL; 1380 1381 /* Fail early if we're missing the AvbOps needed for slot verification. */ 1382 avb_assert(ops->read_is_device_unlocked != NULL); 1383 avb_assert(ops->read_from_partition != NULL); 1384 avb_assert(ops->get_size_of_partition != NULL); 1385 avb_assert(ops->read_rollback_index != NULL); 1386 avb_assert(ops->get_unique_guid_for_partition != NULL); 1387 1388 if (out_data != NULL) { 1389 *out_data = NULL; 1390 } 1391 1392 /* Allowing dm-verity errors defeats the purpose of verified boot so 1393 * only allow this if set up to allow verification errors 1394 * (e.g. typically only UNLOCKED mode). 1395 */ 1396 if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_LOGGING && 1397 !allow_verification_error) { 1398 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1399 goto fail; 1400 } 1401 1402 /* Make sure passed-in AvbOps support persistent values if 1403 * asking for libavb to manage verity state. 1404 */ 1405 if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO) { 1406 if (ops->read_persistent_value == NULL || 1407 ops->write_persistent_value == NULL) { 1408 avb_error( 1409 "Persistent values required for " 1410 "AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO " 1411 "but are not implemented in given AvbOps.\n"); 1412 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1413 goto fail; 1414 } 1415 } 1416 1417 /* Make sure passed-in AvbOps support verifying public keys and getting 1418 * rollback index location if not using a vbmeta partition. 1419 */ 1420 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) { 1421 if (ops->validate_public_key_for_partition == NULL) { 1422 avb_error( 1423 "AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION was passed but the " 1424 "validate_public_key_for_partition() operation isn't implemented.\n"); 1425 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1426 goto fail; 1427 } 1428 } else { 1429 avb_assert(ops->validate_vbmeta_public_key != NULL); 1430 } 1431 1432 slot_data = avb_calloc(sizeof(AvbSlotVerifyData)); 1433 if (slot_data == NULL) { 1434 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1435 goto fail; 1436 } 1437 slot_data->vbmeta_images = 1438 avb_calloc(sizeof(AvbVBMetaData) * MAX_NUMBER_OF_VBMETA_IMAGES); 1439 if (slot_data->vbmeta_images == NULL) { 1440 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1441 goto fail; 1442 } 1443 slot_data->loaded_partitions = 1444 avb_calloc(sizeof(AvbPartitionData) * MAX_NUMBER_OF_LOADED_PARTITIONS); 1445 if (slot_data->loaded_partitions == NULL) { 1446 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1447 goto fail; 1448 } 1449 1450 additional_cmdline_subst = avb_new_cmdline_subst_list(); 1451 if (additional_cmdline_subst == NULL) { 1452 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1453 goto fail; 1454 } 1455 1456 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) { 1457 if (requested_partitions == NULL || requested_partitions[0] == NULL) { 1458 avb_fatal( 1459 "Requested partitions cannot be empty when using " 1460 "AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION"); 1461 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1462 goto fail; 1463 } 1464 1465 /* No vbmeta partition, go through each of the requested partitions... */ 1466 for (size_t n = 0; requested_partitions[n] != NULL; n++) { 1467 ret = load_and_verify_vbmeta(ops, 1468 requested_partitions, 1469 ab_suffix, 1470 flags, 1471 allow_verification_error, 1472 0 /* toplevel_vbmeta_flags */, 1473 0 /* rollback_index_location */, 1474 requested_partitions[n], 1475 avb_strlen(requested_partitions[n]), 1476 NULL /* expected_public_key */, 1477 0 /* expected_public_key_length */, 1478 slot_data, 1479 &algorithm_type, 1480 additional_cmdline_subst); 1481 if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) { 1482 goto fail; 1483 } 1484 } 1485 1486 } else { 1487 /* Usual path, load "vbmeta"... */ 1488 ret = load_and_verify_vbmeta(ops, 1489 requested_partitions, 1490 ab_suffix, 1491 flags, 1492 allow_verification_error, 1493 0 /* toplevel_vbmeta_flags */, 1494 0 /* rollback_index_location */, 1495 "vbmeta", 1496 avb_strlen("vbmeta"), 1497 NULL /* expected_public_key */, 1498 0 /* expected_public_key_length */, 1499 slot_data, 1500 &algorithm_type, 1501 additional_cmdline_subst); 1502 if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) { 1503 goto fail; 1504 } 1505 } 1506 1507 if (!result_should_continue(ret)) { 1508 goto fail; 1509 } 1510 1511 /* If things check out, mangle the kernel command-line as needed. */ 1512 if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) { 1513 if (avb_strcmp(slot_data->vbmeta_images[0].partition_name, "vbmeta") != 0) { 1514 avb_assert( 1515 avb_strcmp(slot_data->vbmeta_images[0].partition_name, "boot") == 0); 1516 using_boot_for_vbmeta = true; 1517 } 1518 } 1519 1520 /* Byteswap top-level vbmeta header since we'll need it below. */ 1521 avb_vbmeta_image_header_to_host_byte_order( 1522 (const AvbVBMetaImageHeader*)slot_data->vbmeta_images[0].vbmeta_data, 1523 &toplevel_vbmeta); 1524 1525 /* Fill in |ab_suffix| field. */ 1526 slot_data->ab_suffix = avb_strdup(ab_suffix); 1527 if (slot_data->ab_suffix == NULL) { 1528 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1529 goto fail; 1530 } 1531 1532 /* If verification is disabled, we are done ... we specifically 1533 * don't want to add any androidboot.* options since verification 1534 * is disabled. 1535 */ 1536 if (toplevel_vbmeta.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) { 1537 /* Since verification is disabled we didn't process any 1538 * descriptors and thus there's no cmdline... so set root= such 1539 * that the system partition is mounted. 1540 */ 1541 avb_assert(slot_data->cmdline == NULL); 1542 // Devices with dynamic partitions won't have system partition. 1543 // Instead, it has a large super partition to accommodate *.img files. 1544 // See b/119551429 for details. 1545 if (has_system_partition(ops, ab_suffix)) { 1546 slot_data->cmdline = 1547 avb_strdup("root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)"); 1548 } else { 1549 // The |cmdline| field should be a NUL-terminated string. 1550 slot_data->cmdline = avb_strdup(""); 1551 } 1552 if (slot_data->cmdline == NULL) { 1553 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1554 goto fail; 1555 } 1556 } else { 1557 /* If requested, manage dm-verity mode... */ 1558 AvbHashtreeErrorMode resolved_hashtree_error_mode = hashtree_error_mode; 1559 if (hashtree_error_mode == 1560 AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO) { 1561 AvbIOResult io_ret; 1562 io_ret = avb_manage_hashtree_error_mode( 1563 ops, flags, slot_data, &resolved_hashtree_error_mode); 1564 if (io_ret != AVB_IO_RESULT_OK) { 1565 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 1566 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 1567 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1568 } 1569 goto fail; 1570 } 1571 } 1572 slot_data->resolved_hashtree_error_mode = resolved_hashtree_error_mode; 1573 1574 /* Add options... */ 1575 AvbSlotVerifyResult sub_ret; 1576 sub_ret = avb_append_options(ops, 1577 flags, 1578 slot_data, 1579 &toplevel_vbmeta, 1580 algorithm_type, 1581 hashtree_error_mode, 1582 resolved_hashtree_error_mode); 1583 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 1584 ret = sub_ret; 1585 goto fail; 1586 } 1587 } 1588 1589 /* Substitute $(ANDROID_SYSTEM_PARTUUID) and friends. */ 1590 if (slot_data->cmdline != NULL && avb_strlen(slot_data->cmdline) != 0) { 1591 char* new_cmdline; 1592 new_cmdline = avb_sub_cmdline(ops, 1593 slot_data->cmdline, 1594 ab_suffix, 1595 using_boot_for_vbmeta, 1596 additional_cmdline_subst); 1597 if (new_cmdline != slot_data->cmdline) { 1598 if (new_cmdline == NULL) { 1599 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1600 goto fail; 1601 } 1602 avb_free(slot_data->cmdline); 1603 slot_data->cmdline = new_cmdline; 1604 } 1605 } 1606 1607 if (out_data != NULL) { 1608 *out_data = slot_data; 1609 } else { 1610 avb_slot_verify_data_free(slot_data); 1611 } 1612 1613 avb_free_cmdline_subst_list(additional_cmdline_subst); 1614 additional_cmdline_subst = NULL; 1615 1616 if (!allow_verification_error) { 1617 avb_assert(ret == AVB_SLOT_VERIFY_RESULT_OK); 1618 } 1619 1620 return ret; 1621 1622 fail: 1623 if (slot_data != NULL) { 1624 avb_slot_verify_data_free(slot_data); 1625 } 1626 if (additional_cmdline_subst != NULL) { 1627 avb_free_cmdline_subst_list(additional_cmdline_subst); 1628 } 1629 return ret; 1630 } 1631 1632 void avb_slot_verify_data_free(AvbSlotVerifyData* data) { 1633 if (data->ab_suffix != NULL) { 1634 avb_free(data->ab_suffix); 1635 } 1636 if (data->cmdline != NULL) { 1637 avb_free(data->cmdline); 1638 } 1639 if (data->vbmeta_images != NULL) { 1640 size_t n; 1641 for (n = 0; n < data->num_vbmeta_images; n++) { 1642 AvbVBMetaData* vbmeta_image = &data->vbmeta_images[n]; 1643 if (vbmeta_image->partition_name != NULL) { 1644 avb_free(vbmeta_image->partition_name); 1645 } 1646 if (vbmeta_image->vbmeta_data != NULL) { 1647 avb_free(vbmeta_image->vbmeta_data); 1648 } 1649 } 1650 avb_free(data->vbmeta_images); 1651 } 1652 if (data->loaded_partitions != NULL) { 1653 size_t n; 1654 for (n = 0; n < data->num_loaded_partitions; n++) { 1655 AvbPartitionData* loaded_partition = &data->loaded_partitions[n]; 1656 if (loaded_partition->partition_name != NULL) { 1657 avb_free(loaded_partition->partition_name); 1658 } 1659 if (loaded_partition->data != NULL && !loaded_partition->preloaded) { 1660 sysmem_free((phys_addr_t)loaded_partition->data); 1661 } 1662 } 1663 avb_free(data->loaded_partitions); 1664 } 1665 avb_free(data); 1666 } 1667 1668 const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result) { 1669 const char* ret = NULL; 1670 1671 switch (result) { 1672 case AVB_SLOT_VERIFY_RESULT_OK: 1673 ret = "OK"; 1674 break; 1675 case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: 1676 ret = "ERROR_OOM"; 1677 break; 1678 case AVB_SLOT_VERIFY_RESULT_ERROR_IO: 1679 ret = "ERROR_IO"; 1680 break; 1681 case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: 1682 ret = "ERROR_VERIFICATION"; 1683 break; 1684 case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: 1685 ret = "ERROR_ROLLBACK_INDEX"; 1686 break; 1687 case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: 1688 ret = "ERROR_PUBLIC_KEY_REJECTED"; 1689 break; 1690 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: 1691 ret = "ERROR_INVALID_METADATA"; 1692 break; 1693 case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: 1694 ret = "ERROR_UNSUPPORTED_VERSION"; 1695 break; 1696 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT: 1697 ret = "ERROR_INVALID_ARGUMENT"; 1698 break; 1699 /* Do not add a 'default:' case here because of -Wswitch. */ 1700 } 1701 1702 if (ret == NULL) { 1703 avb_error("Unknown AvbSlotVerifyResult value.\n"); 1704 ret = "(unknown)"; 1705 } 1706 1707 return ret; 1708 } 1709 1710 void avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData* data, 1711 AvbDigestType digest_type, 1712 uint8_t* out_digest) { 1713 bool ret = false; 1714 size_t n; 1715 1716 switch (digest_type) { 1717 case AVB_DIGEST_TYPE_SHA256: { 1718 AvbSHA256Ctx ctx; 1719 avb_sha256_init(&ctx); 1720 for (n = 0; n < data->num_vbmeta_images; n++) { 1721 avb_sha256_update(&ctx, 1722 data->vbmeta_images[n].vbmeta_data, 1723 data->vbmeta_images[n].vbmeta_size); 1724 } 1725 avb_memcpy(out_digest, avb_sha256_final(&ctx), AVB_SHA256_DIGEST_SIZE); 1726 ret = true; 1727 } break; 1728 1729 case AVB_DIGEST_TYPE_SHA512: { 1730 AvbSHA512Ctx ctx; 1731 avb_sha512_init(&ctx); 1732 for (n = 0; n < data->num_vbmeta_images; n++) { 1733 avb_sha512_update(&ctx, 1734 data->vbmeta_images[n].vbmeta_data, 1735 data->vbmeta_images[n].vbmeta_size); 1736 } 1737 avb_memcpy(out_digest, avb_sha512_final(&ctx), AVB_SHA512_DIGEST_SIZE); 1738 ret = true; 1739 } break; 1740 1741 /* Do not add a 'default:' case here because of -Wswitch. */ 1742 } 1743 1744 if (!ret) { 1745 avb_fatal("Unknown digest type"); 1746 } 1747 } 1748