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 sha256_ctx.tot_len = hash_desc.salt_len + image_size_to_hash; 405 avb_sha256_init(&sha256_ctx); 406 avb_sha256_update(&sha256_ctx, desc_salt, hash_desc.salt_len); 407 avb_sha256_update(&sha256_ctx, image_buf, image_size_to_hash); 408 digest = avb_sha256_final(&sha256_ctx); 409 digest_len = AVB_SHA256_DIGEST_SIZE; 410 } else if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha512") == 0) { 411 sha512_ctx.tot_len = hash_desc.salt_len + image_size_to_hash; 412 avb_sha512_init(&sha512_ctx); 413 avb_sha512_update(&sha512_ctx, desc_salt, hash_desc.salt_len); 414 avb_sha512_update(&sha512_ctx, image_buf, image_size_to_hash); 415 digest = avb_sha512_final(&sha512_ctx); 416 digest_len = AVB_SHA512_DIGEST_SIZE; 417 } else { 418 avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); 419 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 420 goto out; 421 } 422 423 if (hash_desc.digest_len == 0) { 424 /* Expect a match to a persistent digest. */ 425 avb_debugv(part_name, ": No digest, using persistent digest.\n", NULL); 426 expected_digest_len = digest_len; 427 expected_digest = expected_digest_buf; 428 avb_assert(expected_digest_len <= sizeof(expected_digest_buf)); 429 /* Pass |digest| as the |initial_digest| so devices not yet initialized get 430 * initialized to the current partition digest. 431 */ 432 ret = read_persistent_digest( 433 ops, part_name, digest_len, digest, expected_digest_buf); 434 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 435 goto out; 436 } 437 } else { 438 /* Expect a match to the digest in the descriptor. */ 439 expected_digest_len = hash_desc.digest_len; 440 expected_digest = desc_digest; 441 } 442 443 if (digest_len != expected_digest_len) { 444 avb_errorv( 445 part_name, ": Digest in descriptor not of expected size.\n", NULL); 446 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 447 goto out; 448 } 449 450 if (avb_safe_memcmp(digest, expected_digest, digest_len) != 0) { 451 avb_errorv(part_name, 452 ": Hash of data does not match digest in descriptor.\n", 453 NULL); 454 ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; 455 goto out; 456 } 457 458 ret = AVB_SLOT_VERIFY_RESULT_OK; 459 460 out: 461 462 /* If it worked and something was loaded, copy to slot_data. */ 463 if ((ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) && 464 image_buf != NULL) { 465 AvbPartitionData* loaded_partition; 466 if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { 467 avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); 468 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 469 goto fail; 470 } 471 loaded_partition = 472 &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; 473 loaded_partition->partition_name = avb_strdup(found); 474 loaded_partition->data_size = image_size; 475 loaded_partition->data = image_buf; 476 loaded_partition->preloaded = image_preloaded; 477 image_buf = NULL; 478 } 479 480 fail: 481 if (image_buf != NULL && !image_preloaded) { 482 sysmem_free((phys_addr_t)image_buf); 483 } 484 return ret; 485 } 486 487 static AvbSlotVerifyResult load_requested_partitions( 488 AvbOps* ops, 489 const char* const* requested_partitions, 490 const char* ab_suffix, 491 AvbSlotVerifyData* slot_data) { 492 AvbSlotVerifyResult ret; 493 uint8_t* image_buf = NULL; 494 bool image_preloaded = false; 495 size_t n; 496 497 for (n = 0; requested_partitions[n] != NULL; n++) { 498 char part_name[AVB_PART_NAME_MAX_SIZE]; 499 AvbIOResult io_ret; 500 uint64_t image_size; 501 AvbPartitionData* loaded_partition; 502 503 if (!avb_str_concat(part_name, 504 sizeof part_name, 505 requested_partitions[n], 506 avb_strlen(requested_partitions[n]), 507 ab_suffix, 508 avb_strlen(ab_suffix))) { 509 avb_error("Partition name and suffix does not fit.\n"); 510 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 511 goto out; 512 } 513 514 io_ret = ops->get_size_of_partition(ops, part_name, &image_size); 515 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 516 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 517 goto out; 518 } else if (io_ret != AVB_IO_RESULT_OK) { 519 avb_errorv(part_name, ": Error determining partition size.\n", NULL); 520 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 521 goto out; 522 } 523 avb_debugv(part_name, ": Loading entire partition.\n", NULL); 524 525 ret = load_full_partition( 526 ops, part_name, image_size, &image_buf, &image_preloaded, 1); 527 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 528 goto out; 529 } 530 531 /* Move to slot_data. */ 532 if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { 533 avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); 534 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 535 goto out; 536 } 537 loaded_partition = 538 &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; 539 loaded_partition->partition_name = avb_strdup(requested_partitions[n]); 540 if (loaded_partition->partition_name == NULL) { 541 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 542 goto out; 543 } 544 loaded_partition->data_size = image_size; 545 loaded_partition->data = image_buf; /* Transferring the owner. */ 546 loaded_partition->preloaded = image_preloaded; 547 image_buf = NULL; 548 image_preloaded = false; 549 } 550 551 ret = AVB_SLOT_VERIFY_RESULT_OK; 552 553 out: 554 /* Free the current buffer if any. */ 555 if (image_buf != NULL && !image_preloaded) { 556 sysmem_free((phys_addr_t)image_buf); 557 } 558 /* Buffers that are already saved in slot_data will be handled by the caller 559 * even on failure. */ 560 return ret; 561 } 562 563 static AvbSlotVerifyResult load_and_verify_vbmeta( 564 AvbOps* ops, 565 const char* const* requested_partitions, 566 const char* ab_suffix, 567 AvbSlotVerifyFlags flags, 568 bool allow_verification_error, 569 AvbVBMetaImageFlags toplevel_vbmeta_flags, 570 int rollback_index_location, 571 const char* partition_name, 572 size_t partition_name_len, 573 const uint8_t* expected_public_key, 574 size_t expected_public_key_length, 575 AvbSlotVerifyData* slot_data, 576 AvbAlgorithmType* out_algorithm_type, 577 AvbCmdlineSubstList* out_additional_cmdline_subst) { 578 char full_partition_name[AVB_PART_NAME_MAX_SIZE]; 579 AvbSlotVerifyResult ret; 580 AvbIOResult io_ret; 581 uint64_t vbmeta_offset; 582 size_t vbmeta_size; 583 uint8_t* vbmeta_buf = NULL; 584 size_t vbmeta_num_read; 585 AvbVBMetaVerifyResult vbmeta_ret; 586 const uint8_t* pk_data; 587 size_t pk_len; 588 AvbVBMetaImageHeader vbmeta_header; 589 uint64_t stored_rollback_index; 590 const AvbDescriptor** descriptors = NULL; 591 size_t num_descriptors; 592 size_t n; 593 bool is_main_vbmeta; 594 bool look_for_vbmeta_footer; 595 AvbVBMetaData* vbmeta_image_data = NULL; 596 597 ret = AVB_SLOT_VERIFY_RESULT_OK; 598 599 avb_assert(slot_data != NULL); 600 601 /* Since we allow top-level vbmeta in 'boot', use 602 * rollback_index_location to determine whether we're the main 603 * vbmeta struct. 604 */ 605 is_main_vbmeta = false; 606 if (rollback_index_location == 0) { 607 if ((flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) == 0) { 608 is_main_vbmeta = true; 609 } 610 } 611 612 /* Don't use footers for vbmeta partitions ('vbmeta' or 613 * 'vbmeta_<partition_name>'). 614 */ 615 look_for_vbmeta_footer = true; 616 if (avb_strncmp(partition_name, "vbmeta", avb_strlen("vbmeta")) == 0) { 617 look_for_vbmeta_footer = false; 618 } 619 620 if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) { 621 avb_error("Partition name is not valid UTF-8.\n"); 622 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 623 goto out; 624 } 625 626 /* Construct full partition name e.g. system_a. */ 627 if (!avb_str_concat(full_partition_name, 628 sizeof full_partition_name, 629 partition_name, 630 partition_name_len, 631 ab_suffix, 632 avb_strlen(ab_suffix))) { 633 avb_error("Partition name and suffix does not fit.\n"); 634 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 635 goto out; 636 } 637 638 /* If we're loading from the main vbmeta partition, the vbmeta struct is in 639 * the beginning. Otherwise we may have to locate it via a footer... if no 640 * footer is found, we look in the beginning to support e.g. vbmeta_<org> 641 * partitions holding data for e.g. super partitions (b/80195851 for 642 * rationale). 643 */ 644 vbmeta_offset = 0; 645 vbmeta_size = VBMETA_MAX_SIZE; 646 if (look_for_vbmeta_footer) { 647 uint8_t footer_buf[AVB_FOOTER_SIZE]; 648 size_t footer_num_read; 649 AvbFooter footer; 650 651 io_ret = ops->read_from_partition(ops, 652 full_partition_name, 653 -AVB_FOOTER_SIZE, 654 AVB_FOOTER_SIZE, 655 footer_buf, 656 &footer_num_read); 657 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 658 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 659 goto out; 660 } else if (io_ret != AVB_IO_RESULT_OK) { 661 avb_errorv(full_partition_name, ": Error loading footer.\n", NULL); 662 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 663 goto out; 664 } 665 avb_assert(footer_num_read == AVB_FOOTER_SIZE); 666 667 if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf, 668 &footer)) { 669 avb_debugv(full_partition_name, ": No footer detected.\n", NULL); 670 } else { 671 /* Basic footer sanity check since the data is untrusted. */ 672 if (footer.vbmeta_size > VBMETA_MAX_SIZE) { 673 avb_errorv( 674 full_partition_name, ": Invalid vbmeta size in footer.\n", NULL); 675 } else { 676 vbmeta_offset = footer.vbmeta_offset; 677 vbmeta_size = footer.vbmeta_size; 678 } 679 } 680 } 681 682 vbmeta_buf = avb_malloc(vbmeta_size); 683 if (vbmeta_buf == NULL) { 684 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 685 goto out; 686 } 687 688 if (vbmeta_offset != 0) { 689 avb_debugv("Loading vbmeta struct in footer from partition '", 690 full_partition_name, 691 "'.\n", 692 NULL); 693 } else { 694 avb_debugv("Loading vbmeta struct from partition '", 695 full_partition_name, 696 "'.\n", 697 NULL); 698 } 699 700 io_ret = ops->read_from_partition(ops, 701 full_partition_name, 702 vbmeta_offset, 703 vbmeta_size, 704 vbmeta_buf, 705 &vbmeta_num_read); 706 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 707 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 708 goto out; 709 } else if (io_ret != AVB_IO_RESULT_OK) { 710 /* If we're looking for 'vbmeta' but there is no such partition, 711 * go try to get it from the boot partition instead. 712 */ 713 if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION && 714 !look_for_vbmeta_footer) { 715 avb_debugv(full_partition_name, 716 ": No such partition. Trying 'boot' instead.\n", 717 NULL); 718 ret = load_and_verify_vbmeta(ops, 719 requested_partitions, 720 ab_suffix, 721 flags, 722 allow_verification_error, 723 0 /* toplevel_vbmeta_flags */, 724 0 /* rollback_index_location */, 725 "boot", 726 avb_strlen("boot"), 727 NULL /* expected_public_key */, 728 0 /* expected_public_key_length */, 729 slot_data, 730 out_algorithm_type, 731 out_additional_cmdline_subst); 732 goto out; 733 } else { 734 avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL); 735 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 736 goto out; 737 } 738 } 739 avb_assert(vbmeta_num_read <= vbmeta_size); 740 741 /* Check if the image is properly signed and get the public key used 742 * to sign the image. 743 */ 744 vbmeta_ret = 745 avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len); 746 switch (vbmeta_ret) { 747 case AVB_VBMETA_VERIFY_RESULT_OK: 748 avb_assert(pk_data != NULL && pk_len > 0); 749 break; 750 751 case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED: 752 case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH: 753 case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH: 754 ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; 755 avb_errorv(full_partition_name, 756 ": Error verifying vbmeta image: ", 757 avb_vbmeta_verify_result_to_string(vbmeta_ret), 758 "\n", 759 NULL); 760 if (!allow_verification_error) { 761 goto out; 762 } 763 break; 764 765 case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER: 766 /* No way to continue this case. */ 767 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 768 avb_errorv(full_partition_name, 769 ": Error verifying vbmeta image: invalid vbmeta header\n", 770 NULL); 771 goto out; 772 773 case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION: 774 /* No way to continue this case. */ 775 ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION; 776 avb_errorv(full_partition_name, 777 ": Error verifying vbmeta image: unsupported AVB version\n", 778 NULL); 779 goto out; 780 } 781 782 /* Byteswap the header. */ 783 avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf, 784 &vbmeta_header); 785 786 /* If we're the toplevel, assign flags so they'll be passed down. */ 787 if (is_main_vbmeta) { 788 toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags; 789 } else { 790 if (vbmeta_header.flags != 0) { 791 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 792 avb_errorv(full_partition_name, 793 ": chained vbmeta image has non-zero flags\n", 794 NULL); 795 goto out; 796 } 797 } 798 799 uint32_t rollback_index_location_to_use = rollback_index_location; 800 801 /* Check if key used to make signature matches what is expected. */ 802 if (pk_data != NULL) { 803 if (expected_public_key != NULL) { 804 avb_assert(!is_main_vbmeta); 805 if (expected_public_key_length != pk_len || 806 avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) { 807 avb_errorv(full_partition_name, 808 ": Public key used to sign data does not match key in chain " 809 "partition descriptor.\n", 810 NULL); 811 ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; 812 if (!allow_verification_error) { 813 goto out; 814 } 815 } 816 } else { 817 bool key_is_trusted = false; 818 const uint8_t* pk_metadata = NULL; 819 size_t pk_metadata_len = 0; 820 821 if (vbmeta_header.public_key_metadata_size > 0) { 822 pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) + 823 vbmeta_header.authentication_data_block_size + 824 vbmeta_header.public_key_metadata_offset; 825 pk_metadata_len = vbmeta_header.public_key_metadata_size; 826 } 827 828 // If we're not using a vbmeta partition, need to use another AvbOps... 829 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) { 830 io_ret = ops->validate_public_key_for_partition( 831 ops, 832 full_partition_name, 833 pk_data, 834 pk_len, 835 pk_metadata, 836 pk_metadata_len, 837 &key_is_trusted, 838 &rollback_index_location_to_use); 839 } else { 840 avb_assert(is_main_vbmeta); 841 io_ret = ops->validate_vbmeta_public_key(ops, 842 pk_data, 843 pk_len, 844 pk_metadata, 845 pk_metadata_len, 846 &key_is_trusted); 847 } 848 849 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 850 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 851 goto out; 852 } else if (io_ret != AVB_IO_RESULT_OK) { 853 avb_errorv(full_partition_name, 854 ": Error while checking public key used to sign data.\n", 855 NULL); 856 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 857 goto out; 858 } 859 if (!key_is_trusted) { 860 avb_errorv(full_partition_name, 861 ": Public key used to sign data rejected.\n", 862 NULL); 863 ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; 864 if (!allow_verification_error) { 865 goto out; 866 } 867 } 868 } 869 } 870 871 /* Check rollback index. */ 872 io_ret = ops->read_rollback_index( 873 ops, rollback_index_location_to_use, &stored_rollback_index); 874 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 875 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 876 goto out; 877 } else if (io_ret != AVB_IO_RESULT_OK) { 878 avb_errorv(full_partition_name, 879 ": Error getting rollback index for location.\n", 880 NULL); 881 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 882 goto out; 883 } 884 if (vbmeta_header.rollback_index < stored_rollback_index) { 885 avb_errorv( 886 full_partition_name, 887 ": Image rollback index is less than the stored rollback index.\n", 888 NULL); 889 ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX; 890 if (!allow_verification_error) { 891 goto out; 892 } 893 } 894 895 /* Copy vbmeta to vbmeta_images before recursing. */ 896 if (is_main_vbmeta) { 897 avb_assert(slot_data->num_vbmeta_images == 0); 898 } else { 899 if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) { 900 avb_assert(slot_data->num_vbmeta_images > 0); 901 } 902 } 903 if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) { 904 avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL); 905 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 906 goto out; 907 } 908 vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++]; 909 vbmeta_image_data->partition_name = avb_strdup(partition_name); 910 vbmeta_image_data->vbmeta_data = vbmeta_buf; 911 /* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long 912 * and this includes data past the end of the image. Pass the 913 * actual size of the vbmeta image. Also, no need to use 914 * avb_safe_add() since the header has already been verified. 915 */ 916 vbmeta_image_data->vbmeta_size = 917 sizeof(AvbVBMetaImageHeader) + 918 vbmeta_header.authentication_data_block_size + 919 vbmeta_header.auxiliary_data_block_size; 920 vbmeta_image_data->verify_result = vbmeta_ret; 921 922 /* If verification has been disabled by setting a bit in the image, 923 * we're done... except that we need to load the entirety of the 924 * requested partitions. 925 */ 926 if (vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) { 927 AvbSlotVerifyResult sub_ret; 928 avb_debugv( 929 full_partition_name, ": VERIFICATION_DISABLED bit is set.\n", NULL); 930 /* If load_requested_partitions() fail it is always a fatal 931 * failure (e.g. ERROR_INVALID_ARGUMENT, ERROR_OOM, etc.) rather 932 * than recoverable (e.g. one where result_should_continue() 933 * returns true) and we want to convey that error. 934 */ 935 sub_ret = load_requested_partitions( 936 ops, requested_partitions, ab_suffix, slot_data); 937 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 938 ret = sub_ret; 939 } 940 goto out; 941 } 942 943 /* Now go through all descriptors and take the appropriate action: 944 * 945 * - hash descriptor: Load data from partition, calculate hash, and 946 * checks that it matches what's in the hash descriptor. 947 * 948 * - hashtree descriptor: Do nothing since verification happens 949 * on-the-fly from within the OS. (Unless the descriptor uses a 950 * persistent digest, in which case we need to find it). 951 * 952 * - chained partition descriptor: Load the footer, load the vbmeta 953 * image, verify vbmeta image (includes rollback checks, hash 954 * checks, bail on chained partitions). 955 */ 956 descriptors = 957 avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors); 958 for (n = 0; n < num_descriptors; n++) { 959 AvbDescriptor desc; 960 961 if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) { 962 avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL); 963 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 964 goto out; 965 } 966 967 switch (desc.tag) { 968 case AVB_DESCRIPTOR_TAG_HASH: { 969 AvbSlotVerifyResult sub_ret; 970 sub_ret = load_and_verify_hash_partition(ops, 971 requested_partitions, 972 ab_suffix, 973 allow_verification_error, 974 descriptors[n], 975 slot_data); 976 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 977 ret = sub_ret; 978 if (!allow_verification_error || !result_should_continue(ret)) { 979 goto out; 980 } 981 } 982 } break; 983 984 case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: { 985 AvbSlotVerifyResult sub_ret; 986 AvbChainPartitionDescriptor chain_desc; 987 const uint8_t* chain_partition_name; 988 const uint8_t* chain_public_key; 989 990 /* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */ 991 if (!is_main_vbmeta) { 992 avb_errorv(full_partition_name, 993 ": Encountered chain descriptor not in main image.\n", 994 NULL); 995 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 996 goto out; 997 } 998 999 if (!avb_chain_partition_descriptor_validate_and_byteswap( 1000 (AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) { 1001 avb_errorv(full_partition_name, 1002 ": Chain partition descriptor is invalid.\n", 1003 NULL); 1004 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1005 goto out; 1006 } 1007 1008 if (chain_desc.rollback_index_location == 0) { 1009 avb_errorv(full_partition_name, 1010 ": Chain partition has invalid " 1011 "rollback_index_location field.\n", 1012 NULL); 1013 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1014 goto out; 1015 } 1016 1017 chain_partition_name = ((const uint8_t*)descriptors[n]) + 1018 sizeof(AvbChainPartitionDescriptor); 1019 chain_public_key = chain_partition_name + chain_desc.partition_name_len; 1020 1021 sub_ret = 1022 load_and_verify_vbmeta(ops, 1023 requested_partitions, 1024 ab_suffix, 1025 flags, 1026 allow_verification_error, 1027 toplevel_vbmeta_flags, 1028 chain_desc.rollback_index_location, 1029 (const char*)chain_partition_name, 1030 chain_desc.partition_name_len, 1031 chain_public_key, 1032 chain_desc.public_key_len, 1033 slot_data, 1034 NULL, /* out_algorithm_type */ 1035 NULL /* out_additional_cmdline_subst */); 1036 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 1037 ret = sub_ret; 1038 if (!result_should_continue(ret)) { 1039 goto out; 1040 } 1041 } 1042 } break; 1043 1044 case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: { 1045 const uint8_t* kernel_cmdline; 1046 AvbKernelCmdlineDescriptor kernel_cmdline_desc; 1047 bool apply_cmdline; 1048 1049 if (!avb_kernel_cmdline_descriptor_validate_and_byteswap( 1050 (AvbKernelCmdlineDescriptor*)descriptors[n], 1051 &kernel_cmdline_desc)) { 1052 avb_errorv(full_partition_name, 1053 ": Kernel cmdline descriptor is invalid.\n", 1054 NULL); 1055 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1056 goto out; 1057 } 1058 1059 kernel_cmdline = ((const uint8_t*)descriptors[n]) + 1060 sizeof(AvbKernelCmdlineDescriptor); 1061 1062 if (!avb_validate_utf8(kernel_cmdline, 1063 kernel_cmdline_desc.kernel_cmdline_length)) { 1064 avb_errorv(full_partition_name, 1065 ": Kernel cmdline is not valid UTF-8.\n", 1066 NULL); 1067 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1068 goto out; 1069 } 1070 1071 /* Compare the flags for top-level VBMeta struct with flags in 1072 * the command-line descriptor so command-line snippets only 1073 * intended for a certain mode (dm-verity enabled/disabled) 1074 * are skipped if applicable. 1075 */ 1076 apply_cmdline = true; 1077 if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) { 1078 if (kernel_cmdline_desc.flags & 1079 AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) { 1080 apply_cmdline = false; 1081 } 1082 } else { 1083 if (kernel_cmdline_desc.flags & 1084 AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) { 1085 apply_cmdline = false; 1086 } 1087 } 1088 1089 if (apply_cmdline) { 1090 if (slot_data->cmdline == NULL) { 1091 slot_data->cmdline = 1092 avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1); 1093 if (slot_data->cmdline == NULL) { 1094 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1095 goto out; 1096 } 1097 avb_memcpy(slot_data->cmdline, 1098 kernel_cmdline, 1099 kernel_cmdline_desc.kernel_cmdline_length); 1100 } else { 1101 /* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */ 1102 size_t orig_size = avb_strlen(slot_data->cmdline); 1103 size_t new_size = 1104 orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1; 1105 char* new_cmdline = avb_calloc(new_size); 1106 if (new_cmdline == NULL) { 1107 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1108 goto out; 1109 } 1110 avb_memcpy(new_cmdline, slot_data->cmdline, orig_size); 1111 new_cmdline[orig_size] = ' '; 1112 avb_memcpy(new_cmdline + orig_size + 1, 1113 kernel_cmdline, 1114 kernel_cmdline_desc.kernel_cmdline_length); 1115 avb_free(slot_data->cmdline); 1116 slot_data->cmdline = new_cmdline; 1117 } 1118 } 1119 } break; 1120 1121 case AVB_DESCRIPTOR_TAG_HASHTREE: { 1122 AvbHashtreeDescriptor hashtree_desc; 1123 1124 if (!avb_hashtree_descriptor_validate_and_byteswap( 1125 (AvbHashtreeDescriptor*)descriptors[n], &hashtree_desc)) { 1126 avb_errorv( 1127 full_partition_name, ": Hashtree descriptor is invalid.\n", NULL); 1128 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1129 goto out; 1130 } 1131 1132 /* We only need to continue when there is no digest in the descriptor. 1133 * This is because the only processing here is to find the digest and 1134 * make it available on the kernel command line. 1135 */ 1136 if (hashtree_desc.root_digest_len == 0) { 1137 char part_name[AVB_PART_NAME_MAX_SIZE]; 1138 size_t digest_len = 0; 1139 uint8_t digest_buf[AVB_SHA512_DIGEST_SIZE]; 1140 const uint8_t* desc_partition_name = 1141 ((const uint8_t*)descriptors[n]) + sizeof(AvbHashtreeDescriptor); 1142 1143 if (!avb_validate_utf8(desc_partition_name, 1144 hashtree_desc.partition_name_len)) { 1145 avb_error("Partition name is not valid UTF-8.\n"); 1146 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1147 goto out; 1148 } 1149 1150 /* No ab_suffix for partitions without a digest in the descriptor 1151 * because these partitions hold data unique to this device and are 1152 * not updated using an A/B scheme. 1153 */ 1154 if ((hashtree_desc.flags & 1155 AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) == 0 && 1156 avb_strlen(ab_suffix) != 0) { 1157 avb_error("Cannot use A/B with a persistent root digest.\n"); 1158 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1159 goto out; 1160 } 1161 if (hashtree_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) { 1162 avb_error("Partition name does not fit.\n"); 1163 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1164 goto out; 1165 } 1166 avb_memcpy( 1167 part_name, desc_partition_name, hashtree_desc.partition_name_len); 1168 part_name[hashtree_desc.partition_name_len] = '\0'; 1169 1170 /* Determine the expected digest size from the hash algorithm. */ 1171 if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, "sha1") == 1172 0) { 1173 digest_len = AVB_SHA1_DIGEST_SIZE; 1174 } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, 1175 "sha256") == 0) { 1176 digest_len = AVB_SHA256_DIGEST_SIZE; 1177 } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, 1178 "sha512") == 0) { 1179 digest_len = AVB_SHA512_DIGEST_SIZE; 1180 } else { 1181 avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); 1182 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1183 goto out; 1184 } 1185 1186 ret = read_persistent_digest(ops, 1187 part_name, 1188 digest_len, 1189 NULL /* initial_digest */, 1190 digest_buf); 1191 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 1192 goto out; 1193 } 1194 1195 if (out_additional_cmdline_subst) { 1196 ret = 1197 avb_add_root_digest_substitution(part_name, 1198 digest_buf, 1199 digest_len, 1200 out_additional_cmdline_subst); 1201 if (ret != AVB_SLOT_VERIFY_RESULT_OK) { 1202 goto out; 1203 } 1204 } 1205 } 1206 } break; 1207 1208 case AVB_DESCRIPTOR_TAG_PROPERTY: 1209 /* Do nothing. */ 1210 break; 1211 } 1212 } 1213 1214 if (rollback_index_location < 0 || 1215 rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) { 1216 avb_errorv( 1217 full_partition_name, ": Invalid rollback_index_location.\n", NULL); 1218 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; 1219 goto out; 1220 } 1221 1222 slot_data->rollback_indexes[rollback_index_location] = 1223 vbmeta_header.rollback_index; 1224 1225 if (out_algorithm_type != NULL) { 1226 *out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type; 1227 } 1228 1229 out: 1230 /* If |vbmeta_image_data| isn't NULL it means that it adopted 1231 * |vbmeta_buf| so in that case don't free it here. 1232 */ 1233 if (vbmeta_image_data == NULL) { 1234 if (vbmeta_buf != NULL) { 1235 avb_free(vbmeta_buf); 1236 } 1237 } 1238 if (descriptors != NULL) { 1239 avb_free(descriptors); 1240 } 1241 return ret; 1242 } 1243 1244 static AvbIOResult avb_manage_hashtree_error_mode( 1245 AvbOps* ops, 1246 AvbSlotVerifyFlags flags, 1247 AvbSlotVerifyData* data, 1248 AvbHashtreeErrorMode* out_hashtree_error_mode) { 1249 AvbHashtreeErrorMode ret = AVB_HASHTREE_ERROR_MODE_RESTART; 1250 AvbIOResult io_ret = AVB_IO_RESULT_OK; 1251 uint8_t vbmeta_digest_sha256[AVB_SHA256_DIGEST_SIZE]; 1252 uint8_t stored_vbmeta_digest_sha256[AVB_SHA256_DIGEST_SIZE]; 1253 size_t num_bytes_read; 1254 1255 avb_assert(out_hashtree_error_mode != NULL); 1256 avb_assert(ops->read_persistent_value != NULL); 1257 avb_assert(ops->write_persistent_value != NULL); 1258 1259 // If we're rebooting because of dm-verity corruption, make a note of 1260 // the vbmeta hash so we can stay in 'eio' mode until things change. 1261 if (flags & AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION) { 1262 avb_debug( 1263 "Rebooting because of dm-verity corruption - " 1264 "recording OS instance and using 'eio' mode.\n"); 1265 avb_slot_verify_data_calculate_vbmeta_digest( 1266 data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest_sha256); 1267 io_ret = ops->write_persistent_value(ops, 1268 AVB_NPV_MANAGED_VERITY_MODE, 1269 AVB_SHA256_DIGEST_SIZE, 1270 vbmeta_digest_sha256); 1271 if (io_ret != AVB_IO_RESULT_OK) { 1272 avb_error("Error writing to " AVB_NPV_MANAGED_VERITY_MODE ".\n"); 1273 goto out; 1274 } 1275 ret = AVB_HASHTREE_ERROR_MODE_EIO; 1276 io_ret = AVB_IO_RESULT_OK; 1277 goto out; 1278 } 1279 1280 // See if we're in 'eio' mode. 1281 io_ret = ops->read_persistent_value(ops, 1282 AVB_NPV_MANAGED_VERITY_MODE, 1283 AVB_SHA256_DIGEST_SIZE, 1284 stored_vbmeta_digest_sha256, 1285 &num_bytes_read); 1286 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE || 1287 (io_ret == AVB_IO_RESULT_OK && num_bytes_read == 0)) { 1288 // This is the usual case ('eio' mode not set). 1289 avb_debug("No dm-verity corruption - using in 'restart' mode.\n"); 1290 ret = AVB_HASHTREE_ERROR_MODE_RESTART; 1291 io_ret = AVB_IO_RESULT_OK; 1292 goto out; 1293 } else if (io_ret != AVB_IO_RESULT_OK) { 1294 avb_error("Error reading from " AVB_NPV_MANAGED_VERITY_MODE ".\n"); 1295 goto out; 1296 } 1297 if (num_bytes_read != AVB_SHA256_DIGEST_SIZE) { 1298 avb_error( 1299 "Unexpected number of bytes read from " AVB_NPV_MANAGED_VERITY_MODE 1300 ".\n"); 1301 io_ret = AVB_IO_RESULT_ERROR_IO; 1302 goto out; 1303 } 1304 1305 // OK, so we're currently in 'eio' mode and the vbmeta digest of the OS 1306 // that caused this is in |stored_vbmeta_digest_sha256| ... now see if 1307 // the OS we're dealing with now is the same. 1308 avb_slot_verify_data_calculate_vbmeta_digest( 1309 data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest_sha256); 1310 if (avb_memcmp(vbmeta_digest_sha256, 1311 stored_vbmeta_digest_sha256, 1312 AVB_SHA256_DIGEST_SIZE) == 0) { 1313 // It's the same so we're still in 'eio' mode. 1314 avb_debug("Same OS instance detected - staying in 'eio' mode.\n"); 1315 ret = AVB_HASHTREE_ERROR_MODE_EIO; 1316 io_ret = AVB_IO_RESULT_OK; 1317 } else { 1318 // It did change! 1319 avb_debug( 1320 "New OS instance detected - changing from 'eio' to 'restart' mode.\n"); 1321 io_ret = 1322 ops->write_persistent_value(ops, 1323 AVB_NPV_MANAGED_VERITY_MODE, 1324 0, // This clears the persistent property. 1325 vbmeta_digest_sha256); 1326 if (io_ret != AVB_IO_RESULT_OK) { 1327 avb_error("Error clearing " AVB_NPV_MANAGED_VERITY_MODE ".\n"); 1328 goto out; 1329 } 1330 ret = AVB_HASHTREE_ERROR_MODE_RESTART; 1331 io_ret = AVB_IO_RESULT_OK; 1332 } 1333 1334 out: 1335 *out_hashtree_error_mode = ret; 1336 return io_ret; 1337 } 1338 1339 static bool has_system_partition(AvbOps* ops, const char* ab_suffix) { 1340 char part_name[AVB_PART_NAME_MAX_SIZE]; 1341 char* system_part_name = "system"; 1342 char guid_buf[37]; 1343 AvbIOResult io_ret; 1344 1345 if (!avb_str_concat(part_name, 1346 sizeof part_name, 1347 system_part_name, 1348 avb_strlen(system_part_name), 1349 ab_suffix, 1350 avb_strlen(ab_suffix))) { 1351 avb_error("System partition name and suffix does not fit.\n"); 1352 return false; 1353 } 1354 1355 io_ret = ops->get_unique_guid_for_partition( 1356 ops, part_name, guid_buf, sizeof guid_buf); 1357 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION) { 1358 avb_debug("No system partition.\n"); 1359 return false; 1360 } else if (io_ret != AVB_IO_RESULT_OK) { 1361 avb_error("Error getting unique GUID for system partition.\n"); 1362 return false; 1363 } 1364 1365 return true; 1366 } 1367 1368 AvbSlotVerifyResult avb_slot_verify(AvbOps* ops, 1369 const char* const* requested_partitions, 1370 const char* ab_suffix, 1371 AvbSlotVerifyFlags flags, 1372 AvbHashtreeErrorMode hashtree_error_mode, 1373 AvbSlotVerifyData** out_data) { 1374 AvbSlotVerifyResult ret = 0; 1375 AvbSlotVerifyData* slot_data = NULL; 1376 AvbAlgorithmType algorithm_type = AVB_ALGORITHM_TYPE_NONE; 1377 bool using_boot_for_vbmeta = false; 1378 AvbVBMetaImageHeader toplevel_vbmeta; 1379 bool allow_verification_error = 1380 (flags & AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR); 1381 AvbCmdlineSubstList* additional_cmdline_subst = NULL; 1382 1383 /* Fail early if we're missing the AvbOps needed for slot verification. */ 1384 avb_assert(ops->read_is_device_unlocked != NULL); 1385 avb_assert(ops->read_from_partition != NULL); 1386 avb_assert(ops->get_size_of_partition != NULL); 1387 avb_assert(ops->read_rollback_index != NULL); 1388 avb_assert(ops->get_unique_guid_for_partition != NULL); 1389 1390 if (out_data != NULL) { 1391 *out_data = NULL; 1392 } 1393 1394 /* Allowing dm-verity errors defeats the purpose of verified boot so 1395 * only allow this if set up to allow verification errors 1396 * (e.g. typically only UNLOCKED mode). 1397 */ 1398 if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_LOGGING && 1399 !allow_verification_error) { 1400 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1401 goto fail; 1402 } 1403 1404 /* Make sure passed-in AvbOps support persistent values if 1405 * asking for libavb to manage verity state. 1406 */ 1407 if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO) { 1408 if (ops->read_persistent_value == NULL || 1409 ops->write_persistent_value == NULL) { 1410 avb_error( 1411 "Persistent values required for " 1412 "AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO " 1413 "but are not implemented in given AvbOps.\n"); 1414 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1415 goto fail; 1416 } 1417 } 1418 1419 /* Make sure passed-in AvbOps support verifying public keys and getting 1420 * rollback index location if not using a vbmeta partition. 1421 */ 1422 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) { 1423 if (ops->validate_public_key_for_partition == NULL) { 1424 avb_error( 1425 "AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION was passed but the " 1426 "validate_public_key_for_partition() operation isn't implemented.\n"); 1427 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1428 goto fail; 1429 } 1430 } else { 1431 avb_assert(ops->validate_vbmeta_public_key != NULL); 1432 } 1433 1434 slot_data = avb_calloc(sizeof(AvbSlotVerifyData)); 1435 if (slot_data == NULL) { 1436 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1437 goto fail; 1438 } 1439 slot_data->vbmeta_images = 1440 avb_calloc(sizeof(AvbVBMetaData) * MAX_NUMBER_OF_VBMETA_IMAGES); 1441 if (slot_data->vbmeta_images == NULL) { 1442 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1443 goto fail; 1444 } 1445 slot_data->loaded_partitions = 1446 avb_calloc(sizeof(AvbPartitionData) * MAX_NUMBER_OF_LOADED_PARTITIONS); 1447 if (slot_data->loaded_partitions == NULL) { 1448 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1449 goto fail; 1450 } 1451 1452 additional_cmdline_subst = avb_new_cmdline_subst_list(); 1453 if (additional_cmdline_subst == NULL) { 1454 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1455 goto fail; 1456 } 1457 1458 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) { 1459 if (requested_partitions == NULL || requested_partitions[0] == NULL) { 1460 avb_fatal( 1461 "Requested partitions cannot be empty when using " 1462 "AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION"); 1463 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; 1464 goto fail; 1465 } 1466 1467 /* No vbmeta partition, go through each of the requested partitions... */ 1468 for (size_t n = 0; requested_partitions[n] != NULL; n++) { 1469 ret = load_and_verify_vbmeta(ops, 1470 requested_partitions, 1471 ab_suffix, 1472 flags, 1473 allow_verification_error, 1474 0 /* toplevel_vbmeta_flags */, 1475 0 /* rollback_index_location */, 1476 requested_partitions[n], 1477 avb_strlen(requested_partitions[n]), 1478 NULL /* expected_public_key */, 1479 0 /* expected_public_key_length */, 1480 slot_data, 1481 &algorithm_type, 1482 additional_cmdline_subst); 1483 if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) { 1484 goto fail; 1485 } 1486 } 1487 1488 } else { 1489 /* Usual path, load "vbmeta"... */ 1490 ret = load_and_verify_vbmeta(ops, 1491 requested_partitions, 1492 ab_suffix, 1493 flags, 1494 allow_verification_error, 1495 0 /* toplevel_vbmeta_flags */, 1496 0 /* rollback_index_location */, 1497 "vbmeta", 1498 avb_strlen("vbmeta"), 1499 NULL /* expected_public_key */, 1500 0 /* expected_public_key_length */, 1501 slot_data, 1502 &algorithm_type, 1503 additional_cmdline_subst); 1504 if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) { 1505 goto fail; 1506 } 1507 } 1508 1509 if (!result_should_continue(ret)) { 1510 goto fail; 1511 } 1512 1513 /* If things check out, mangle the kernel command-line as needed. */ 1514 if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) { 1515 if (avb_strcmp(slot_data->vbmeta_images[0].partition_name, "vbmeta") != 0) { 1516 avb_assert( 1517 avb_strcmp(slot_data->vbmeta_images[0].partition_name, "boot") == 0); 1518 using_boot_for_vbmeta = true; 1519 } 1520 } 1521 1522 /* Byteswap top-level vbmeta header since we'll need it below. */ 1523 avb_vbmeta_image_header_to_host_byte_order( 1524 (const AvbVBMetaImageHeader*)slot_data->vbmeta_images[0].vbmeta_data, 1525 &toplevel_vbmeta); 1526 1527 /* Fill in |ab_suffix| field. */ 1528 slot_data->ab_suffix = avb_strdup(ab_suffix); 1529 if (slot_data->ab_suffix == NULL) { 1530 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1531 goto fail; 1532 } 1533 1534 /* If verification is disabled, we are done ... we specifically 1535 * don't want to add any androidboot.* options since verification 1536 * is disabled. 1537 */ 1538 if (toplevel_vbmeta.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) { 1539 /* Since verification is disabled we didn't process any 1540 * descriptors and thus there's no cmdline... so set root= such 1541 * that the system partition is mounted. 1542 */ 1543 avb_assert(slot_data->cmdline == NULL); 1544 // Devices with dynamic partitions won't have system partition. 1545 // Instead, it has a large super partition to accommodate *.img files. 1546 // See b/119551429 for details. 1547 if (has_system_partition(ops, ab_suffix)) { 1548 slot_data->cmdline = 1549 avb_strdup("root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)"); 1550 } else { 1551 // The |cmdline| field should be a NUL-terminated string. 1552 slot_data->cmdline = avb_strdup(""); 1553 } 1554 if (slot_data->cmdline == NULL) { 1555 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1556 goto fail; 1557 } 1558 } else { 1559 /* If requested, manage dm-verity mode... */ 1560 AvbHashtreeErrorMode resolved_hashtree_error_mode = hashtree_error_mode; 1561 if (hashtree_error_mode == 1562 AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO) { 1563 AvbIOResult io_ret; 1564 io_ret = avb_manage_hashtree_error_mode( 1565 ops, flags, slot_data, &resolved_hashtree_error_mode); 1566 if (io_ret != AVB_IO_RESULT_OK) { 1567 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; 1568 if (io_ret == AVB_IO_RESULT_ERROR_OOM) { 1569 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1570 } 1571 goto fail; 1572 } 1573 } 1574 slot_data->resolved_hashtree_error_mode = resolved_hashtree_error_mode; 1575 1576 /* Add options... */ 1577 AvbSlotVerifyResult sub_ret; 1578 sub_ret = avb_append_options(ops, 1579 flags, 1580 slot_data, 1581 &toplevel_vbmeta, 1582 algorithm_type, 1583 hashtree_error_mode, 1584 resolved_hashtree_error_mode); 1585 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { 1586 ret = sub_ret; 1587 goto fail; 1588 } 1589 } 1590 1591 /* Substitute $(ANDROID_SYSTEM_PARTUUID) and friends. */ 1592 if (slot_data->cmdline != NULL && avb_strlen(slot_data->cmdline) != 0) { 1593 char* new_cmdline; 1594 new_cmdline = avb_sub_cmdline(ops, 1595 slot_data->cmdline, 1596 ab_suffix, 1597 using_boot_for_vbmeta, 1598 additional_cmdline_subst); 1599 if (new_cmdline != slot_data->cmdline) { 1600 if (new_cmdline == NULL) { 1601 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; 1602 goto fail; 1603 } 1604 avb_free(slot_data->cmdline); 1605 slot_data->cmdline = new_cmdline; 1606 } 1607 } 1608 1609 if (out_data != NULL) { 1610 *out_data = slot_data; 1611 } else { 1612 avb_slot_verify_data_free(slot_data); 1613 } 1614 1615 avb_free_cmdline_subst_list(additional_cmdline_subst); 1616 additional_cmdline_subst = NULL; 1617 1618 if (!allow_verification_error) { 1619 avb_assert(ret == AVB_SLOT_VERIFY_RESULT_OK); 1620 } 1621 1622 return ret; 1623 1624 fail: 1625 if (slot_data != NULL) { 1626 avb_slot_verify_data_free(slot_data); 1627 } 1628 if (additional_cmdline_subst != NULL) { 1629 avb_free_cmdline_subst_list(additional_cmdline_subst); 1630 } 1631 return ret; 1632 } 1633 1634 void avb_slot_verify_data_free(AvbSlotVerifyData* data) { 1635 if (data->ab_suffix != NULL) { 1636 avb_free(data->ab_suffix); 1637 } 1638 if (data->cmdline != NULL) { 1639 avb_free(data->cmdline); 1640 } 1641 if (data->vbmeta_images != NULL) { 1642 size_t n; 1643 for (n = 0; n < data->num_vbmeta_images; n++) { 1644 AvbVBMetaData* vbmeta_image = &data->vbmeta_images[n]; 1645 if (vbmeta_image->partition_name != NULL) { 1646 avb_free(vbmeta_image->partition_name); 1647 } 1648 if (vbmeta_image->vbmeta_data != NULL) { 1649 avb_free(vbmeta_image->vbmeta_data); 1650 } 1651 } 1652 avb_free(data->vbmeta_images); 1653 } 1654 if (data->loaded_partitions != NULL) { 1655 size_t n; 1656 for (n = 0; n < data->num_loaded_partitions; n++) { 1657 AvbPartitionData* loaded_partition = &data->loaded_partitions[n]; 1658 if (loaded_partition->partition_name != NULL) { 1659 avb_free(loaded_partition->partition_name); 1660 } 1661 if (loaded_partition->data != NULL && !loaded_partition->preloaded) { 1662 sysmem_free((phys_addr_t)loaded_partition->data); 1663 } 1664 } 1665 avb_free(data->loaded_partitions); 1666 } 1667 avb_free(data); 1668 } 1669 1670 const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result) { 1671 const char* ret = NULL; 1672 1673 switch (result) { 1674 case AVB_SLOT_VERIFY_RESULT_OK: 1675 ret = "OK"; 1676 break; 1677 case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: 1678 ret = "ERROR_OOM"; 1679 break; 1680 case AVB_SLOT_VERIFY_RESULT_ERROR_IO: 1681 ret = "ERROR_IO"; 1682 break; 1683 case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: 1684 ret = "ERROR_VERIFICATION"; 1685 break; 1686 case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: 1687 ret = "ERROR_ROLLBACK_INDEX"; 1688 break; 1689 case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: 1690 ret = "ERROR_PUBLIC_KEY_REJECTED"; 1691 break; 1692 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: 1693 ret = "ERROR_INVALID_METADATA"; 1694 break; 1695 case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: 1696 ret = "ERROR_UNSUPPORTED_VERSION"; 1697 break; 1698 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT: 1699 ret = "ERROR_INVALID_ARGUMENT"; 1700 break; 1701 /* Do not add a 'default:' case here because of -Wswitch. */ 1702 } 1703 1704 if (ret == NULL) { 1705 avb_error("Unknown AvbSlotVerifyResult value.\n"); 1706 ret = "(unknown)"; 1707 } 1708 1709 return ret; 1710 } 1711 1712 void avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData* data, 1713 AvbDigestType digest_type, 1714 uint8_t* out_digest) { 1715 bool ret = false; 1716 size_t n; 1717 1718 switch (digest_type) { 1719 case AVB_DIGEST_TYPE_SHA256: { 1720 AvbSHA256Ctx ctx; 1721 1722 ctx.tot_len = 0; 1723 for (n = 0; n < data->num_vbmeta_images; n++) 1724 ctx.tot_len += data->vbmeta_images[n].vbmeta_size; 1725 1726 avb_sha256_init(&ctx); 1727 for (n = 0; n < data->num_vbmeta_images; n++) { 1728 avb_sha256_update(&ctx, 1729 data->vbmeta_images[n].vbmeta_data, 1730 data->vbmeta_images[n].vbmeta_size); 1731 } 1732 avb_memcpy(out_digest, avb_sha256_final(&ctx), AVB_SHA256_DIGEST_SIZE); 1733 ret = true; 1734 } break; 1735 1736 case AVB_DIGEST_TYPE_SHA512: { 1737 AvbSHA512Ctx ctx; 1738 1739 ctx.tot_len = 0; 1740 for (n = 0; n < data->num_vbmeta_images; n++) 1741 ctx.tot_len += data->vbmeta_images[n].vbmeta_size; 1742 1743 avb_sha512_init(&ctx); 1744 for (n = 0; n < data->num_vbmeta_images; n++) { 1745 avb_sha512_update(&ctx, 1746 data->vbmeta_images[n].vbmeta_data, 1747 data->vbmeta_images[n].vbmeta_size); 1748 } 1749 avb_memcpy(out_digest, avb_sha512_final(&ctx), AVB_SHA512_DIGEST_SIZE); 1750 ret = true; 1751 } break; 1752 1753 /* Do not add a 'default:' case here because of -Wswitch. */ 1754 } 1755 1756 if (!ret) { 1757 avb_fatal("Unknown digest type"); 1758 } 1759 } 1760