| // SPDX-License-Identifier: MIT |
| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| */ |
| |
| #include "avb_slot_verify.h" |
| #include "avb_chain_partition_descriptor.h" |
| #include "avb_cmdline.h" |
| #include "avb_footer.h" |
| #include "avb_hash_descriptor.h" |
| #include "avb_hashtree_descriptor.h" |
| #include "avb_kernel_cmdline_descriptor.h" |
| #include "avb_sha.h" |
| #include "avb_util.h" |
| #include "avb_vbmeta_image.h" |
| #include "avb_version.h" |
| #if defined(CONFIG_IMX_TRUSTY_OS) && !defined(CONFIG_AVB_ATX) |
| #include "trusty/hwcrypto.h" |
| #include <memalign.h> |
| #endif |
| |
| /* Maximum number of partitions that can be loaded with avb_slot_verify(). */ |
| #define MAX_NUMBER_OF_LOADED_PARTITIONS 32 |
| |
| /* Maximum number of vbmeta images that can be loaded with avb_slot_verify(). */ |
| #define MAX_NUMBER_OF_VBMETA_IMAGES 32 |
| |
| /* Maximum size of a vbmeta image - 64 KiB. */ |
| #define VBMETA_MAX_SIZE (64 * 1024) |
| |
| /* Helper function to see if we should continue with verification in |
| * allow_verification_error=true mode if something goes wrong. See the |
| * comments for the avb_slot_verify() function for more information. |
| */ |
| static inline bool result_should_continue(AvbSlotVerifyResult result) { |
| switch (result) { |
| case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_IO: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT: |
| return false; |
| |
| case AVB_SLOT_VERIFY_RESULT_OK: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: |
| case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static AvbSlotVerifyResult load_full_partition(AvbOps* ops, |
| const char* part_name, |
| uint64_t image_size, |
| uint8_t** out_image_buf, |
| bool* out_image_preloaded) { |
| size_t part_num_read; |
| AvbIOResult io_ret; |
| |
| /* Make sure that we do not overwrite existing data. */ |
| avb_assert(*out_image_buf == NULL); |
| avb_assert(!*out_image_preloaded); |
| |
| /* We are going to implicitly cast image_size from uint64_t to size_t in the |
| * following code, so we need to make sure that the cast is safe. */ |
| if (image_size != (size_t)(image_size)) { |
| avb_errorv(part_name, ": Partition size too large to load.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| } |
| |
| /* Try use a preloaded one. */ |
| if (ops->get_preloaded_partition != NULL) { |
| io_ret = ops->get_preloaded_partition( |
| ops, part_name, image_size, out_image_buf, &part_num_read); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(part_name, ": Error loading data from partition.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| } |
| |
| if (*out_image_buf != NULL) { |
| if (part_num_read != image_size) { |
| avb_errorv(part_name, ": Read incorrect number of bytes.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| } |
| *out_image_preloaded = true; |
| } |
| } |
| |
| /* Allocate and copy the partition. */ |
| if (!*out_image_preloaded) { |
| *out_image_buf = avb_malloc(image_size); |
| if (*out_image_buf == NULL) { |
| return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| } |
| |
| io_ret = ops->read_from_partition(ops, |
| part_name, |
| 0 /* offset */, |
| image_size, |
| *out_image_buf, |
| &part_num_read); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(part_name, ": Error loading data from partition.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| } |
| if (part_num_read != image_size) { |
| avb_errorv(part_name, ": Read incorrect number of bytes.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| } |
| } |
| |
| return AVB_SLOT_VERIFY_RESULT_OK; |
| } |
| |
| static AvbSlotVerifyResult read_persistent_digest(AvbOps* ops, |
| const char* part_name, |
| size_t expected_digest_size, |
| uint8_t* out_digest) { |
| char* persistent_value_name = NULL; |
| AvbIOResult io_ret = AVB_IO_RESULT_OK; |
| size_t stored_digest_size = 0; |
| |
| if (ops->read_persistent_value == NULL) { |
| avb_errorv(part_name, ": Persistent values are not implemented.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| } |
| persistent_value_name = |
| avb_strdupv(AVB_NPV_PERSISTENT_DIGEST_PREFIX, part_name, NULL); |
| if (persistent_value_name == NULL) { |
| return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| } |
| io_ret = ops->read_persistent_value(ops, |
| persistent_value_name, |
| expected_digest_size, |
| out_digest, |
| &stored_digest_size); |
| avb_free(persistent_value_name); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| return AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| } else if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE) { |
| avb_errorv(part_name, ": Persistent digest does not exist.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| } else if (io_ret == AVB_IO_RESULT_ERROR_INVALID_VALUE_SIZE || |
| io_ret == AVB_IO_RESULT_ERROR_INSUFFICIENT_SPACE || |
| expected_digest_size != stored_digest_size) { |
| avb_errorv( |
| part_name, ": Persistent digest is not of expected size.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(part_name, ": Error reading persistent digest.\n", NULL); |
| return AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| } |
| return AVB_SLOT_VERIFY_RESULT_OK; |
| } |
| |
| static AvbSlotVerifyResult load_and_verify_hash_partition( |
| AvbOps* ops, |
| const char* const* requested_partitions, |
| const char* ab_suffix, |
| bool allow_verification_error, |
| const AvbDescriptor* descriptor, |
| AvbSlotVerifyData* slot_data) { |
| AvbHashDescriptor hash_desc; |
| const uint8_t* desc_partition_name = NULL; |
| const uint8_t* desc_salt; |
| const uint8_t* desc_digest; |
| char part_name[AVB_PART_NAME_MAX_SIZE]; |
| AvbSlotVerifyResult ret; |
| AvbIOResult io_ret; |
| uint8_t* image_buf = NULL; |
| bool image_preloaded = false; |
| uint8_t* digest; |
| size_t digest_len; |
| const char* found; |
| uint64_t image_size; |
| size_t expected_digest_len = 0; |
| uint8_t expected_digest_buf[AVB_SHA512_DIGEST_SIZE]; |
| const uint8_t* expected_digest = NULL; |
| #if defined(CONFIG_IMX_TRUSTY_OS) && !defined(CONFIG_AVB_ATX) |
| uint8_t* hash_out = NULL; |
| uint8_t* hash_buf = NULL; |
| #endif |
| |
| |
| if (!avb_hash_descriptor_validate_and_byteswap( |
| (const AvbHashDescriptor*)descriptor, &hash_desc)) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| desc_partition_name = |
| ((const uint8_t*)descriptor) + sizeof(AvbHashDescriptor); |
| desc_salt = desc_partition_name + hash_desc.partition_name_len; |
| desc_digest = desc_salt + hash_desc.salt_len; |
| |
| if (!avb_validate_utf8(desc_partition_name, hash_desc.partition_name_len)) { |
| avb_error("Partition name is not valid UTF-8.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| /* Don't bother loading or validating unless the partition was |
| * requested in the first place. |
| */ |
| found = avb_strv_find_str(requested_partitions, |
| (const char*)desc_partition_name, |
| hash_desc.partition_name_len); |
| if (found == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_OK; |
| goto out; |
| } |
| |
| if ((hash_desc.flags & AVB_HASH_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) != 0) { |
| /* No ab_suffix, just copy the partition name as is. */ |
| if (hash_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) { |
| avb_error("Partition name does not fit.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| avb_memcpy(part_name, desc_partition_name, hash_desc.partition_name_len); |
| part_name[hash_desc.partition_name_len] = '\0'; |
| } else if (hash_desc.digest_len == 0 && avb_strlen(ab_suffix) != 0) { |
| /* No ab_suffix allowed for partitions without a digest in the descriptor |
| * because these partitions hold data unique to this device and are not |
| * updated using an A/B scheme. |
| */ |
| avb_error("Cannot use A/B with a persistent digest.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } else { |
| /* Add ab_suffix to the partition name. */ |
| if (!avb_str_concat(part_name, |
| sizeof part_name, |
| (const char*)desc_partition_name, |
| hash_desc.partition_name_len, |
| ab_suffix, |
| avb_strlen(ab_suffix))) { |
| avb_error("Partition name and suffix does not fit.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| } |
| |
| /* If we're allowing verification errors then hash_desc.image_size |
| * may no longer match what's in the partition... so in this case |
| * just load the entire partition. |
| * |
| * For example, this can happen if a developer does 'fastboot flash |
| * boot /path/to/new/and/bigger/boot.img'. We want this to work |
| * since it's such a common workflow. |
| */ |
| image_size = hash_desc.image_size; |
| if (allow_verification_error) { |
| if (ops->get_size_of_partition == NULL) { |
| avb_errorv(part_name, |
| ": The get_size_of_partition() operation is " |
| "not implemented so we may not load the entire partition. " |
| "Please implement.", |
| NULL); |
| } else { |
| io_ret = ops->get_size_of_partition(ops, part_name, &image_size); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(part_name, ": Error determining partition size.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| goto out; |
| } |
| avb_debugv(part_name, ": Loading entire partition.\n", NULL); |
| } |
| } |
| |
| ret = load_full_partition( |
| ops, part_name, image_size, &image_buf, &image_preloaded); |
| if (ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| goto out; |
| } |
| |
| if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha256") == 0) { |
| #if defined(CONFIG_IMX_TRUSTY_OS) && !defined(CONFIG_AVB_ATX) |
| /* DMA requires cache aligned input/output buffer */ |
| hash_out = memalign(ARCH_DMA_MINALIGN, AVB_SHA256_DIGEST_SIZE); |
| if (hash_out == NULL) { |
| avb_error("failed to alloc memory!\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| uint32_t round_buf_size = ROUND(hash_desc.salt_len + hash_desc.image_size, |
| ARCH_DMA_MINALIGN); |
| hash_buf = memalign(ARCH_DMA_MINALIGN, round_buf_size); |
| if (hash_buf == NULL) { |
| avb_error("failed to alloc memory!\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| |
| avb_memcpy(hash_buf, desc_salt, hash_desc.salt_len); |
| avb_memcpy(hash_buf + hash_desc.salt_len, |
| image_buf, hash_desc.image_size); |
| /* calculate sha256 hash by caam */ |
| if (hwcrypto_hash((uint32_t)(ulong)hash_buf, |
| (hash_desc.salt_len + hash_desc.image_size), |
| (uint32_t)(ulong)hash_out, |
| AVB_SHA256_DIGEST_SIZE, |
| SHA256) != 0) { |
| avb_error("Failed to calculate sha256 hash with caam.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; |
| goto out; |
| } |
| |
| digest = hash_out; |
| free(hash_buf); |
| hash_buf = NULL; |
| #else |
| AvbSHA256Ctx sha256_ctx; |
| avb_sha256_init(&sha256_ctx); |
| avb_sha256_update(&sha256_ctx, desc_salt, hash_desc.salt_len); |
| avb_sha256_update(&sha256_ctx, image_buf, hash_desc.image_size); |
| digest = avb_sha256_final(&sha256_ctx); |
| #endif |
| digest_len = AVB_SHA256_DIGEST_SIZE; |
| } else if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha512") == 0) { |
| AvbSHA512Ctx sha512_ctx; |
| avb_sha512_init(&sha512_ctx); |
| avb_sha512_update(&sha512_ctx, desc_salt, hash_desc.salt_len); |
| avb_sha512_update(&sha512_ctx, image_buf, hash_desc.image_size); |
| digest = avb_sha512_final(&sha512_ctx); |
| digest_len = AVB_SHA512_DIGEST_SIZE; |
| } else { |
| avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| if (hash_desc.digest_len == 0) { |
| // Expect a match to a persistent digest. |
| avb_debugv(part_name, ": No digest, using persistent digest.\n", NULL); |
| expected_digest_len = digest_len; |
| expected_digest = expected_digest_buf; |
| avb_assert(expected_digest_len <= sizeof(expected_digest_buf)); |
| ret = |
| read_persistent_digest(ops, part_name, digest_len, expected_digest_buf); |
| if (ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| goto out; |
| } |
| } else { |
| // Expect a match to the digest in the descriptor. |
| expected_digest_len = hash_desc.digest_len; |
| expected_digest = desc_digest; |
| } |
| |
| if (digest_len != expected_digest_len) { |
| avb_errorv( |
| part_name, ": Digest in descriptor not of expected size.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| if (avb_safe_memcmp(digest, expected_digest, digest_len) != 0) { |
| avb_errorv(part_name, |
| ": Hash of data does not match digest in descriptor.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; |
| goto out; |
| } |
| |
| ret = AVB_SLOT_VERIFY_RESULT_OK; |
| |
| out: |
| |
| #if defined(CONFIG_IMX_TRUSTY_OS) && !defined(CONFIG_AVB_ATX) |
| if (hash_out != NULL) { |
| free(hash_out); |
| hash_out = NULL; |
| } |
| if (hash_buf != NULL) { |
| free(hash_buf); |
| hash_buf = NULL; |
| } |
| #endif |
| /* If it worked and something was loaded, copy to slot_data. */ |
| if ((ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) && |
| image_buf != NULL) { |
| AvbPartitionData* loaded_partition; |
| if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { |
| avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| loaded_partition = |
| &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; |
| loaded_partition->partition_name = avb_strdup(found); |
| loaded_partition->data_size = image_size; |
| loaded_partition->data = image_buf; |
| loaded_partition->preloaded = image_preloaded; |
| image_buf = NULL; |
| } |
| |
| fail: |
| if (image_buf != NULL && !image_preloaded) { |
| avb_free(image_buf); |
| } |
| return ret; |
| } |
| |
| static AvbSlotVerifyResult load_requested_partitions( |
| AvbOps* ops, |
| const char* const* requested_partitions, |
| const char* ab_suffix, |
| AvbSlotVerifyData* slot_data) { |
| AvbSlotVerifyResult ret; |
| uint8_t* image_buf = NULL; |
| bool image_preloaded = false; |
| size_t n; |
| |
| if (ops->get_size_of_partition == NULL) { |
| avb_error("get_size_of_partition() not implemented.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; |
| goto out; |
| } |
| |
| for (n = 0; requested_partitions[n] != NULL; n++) { |
| char part_name[AVB_PART_NAME_MAX_SIZE]; |
| AvbIOResult io_ret; |
| uint64_t image_size; |
| AvbPartitionData* loaded_partition; |
| |
| if (!avb_str_concat(part_name, |
| sizeof part_name, |
| requested_partitions[n], |
| avb_strlen(requested_partitions[n]), |
| ab_suffix, |
| avb_strlen(ab_suffix))) { |
| avb_error("Partition name and suffix does not fit.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| io_ret = ops->get_size_of_partition(ops, part_name, &image_size); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(part_name, ": Error determining partition size.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| goto out; |
| } |
| avb_debugv(part_name, ": Loading entire partition.\n", NULL); |
| |
| ret = load_full_partition( |
| ops, part_name, image_size, &image_buf, &image_preloaded); |
| if (ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| goto out; |
| } |
| |
| /* Move to slot_data. */ |
| if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { |
| avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| loaded_partition = |
| &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; |
| loaded_partition->partition_name = avb_strdup(requested_partitions[n]); |
| if (loaded_partition->partition_name == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| loaded_partition->data_size = image_size; |
| loaded_partition->data = image_buf; /* Transferring the owner. */ |
| loaded_partition->preloaded = image_preloaded; |
| image_buf = NULL; |
| image_preloaded = false; |
| } |
| |
| ret = AVB_SLOT_VERIFY_RESULT_OK; |
| |
| out: |
| /* Free the current buffer if any. */ |
| if (image_buf != NULL && !image_preloaded) { |
| avb_free(image_buf); |
| } |
| /* Buffers that are already saved in slot_data will be handled by the caller |
| * even on failure. */ |
| return ret; |
| } |
| |
| static AvbSlotVerifyResult load_and_verify_vbmeta( |
| AvbOps* ops, |
| const char* const* requested_partitions, |
| const char* ab_suffix, |
| bool allow_verification_error, |
| AvbVBMetaImageFlags toplevel_vbmeta_flags, |
| int rollback_index_location, |
| const char* partition_name, |
| size_t partition_name_len, |
| const uint8_t* expected_public_key, |
| size_t expected_public_key_length, |
| AvbSlotVerifyData* slot_data, |
| AvbAlgorithmType* out_algorithm_type, |
| AvbCmdlineSubstList* out_additional_cmdline_subst) { |
| char full_partition_name[AVB_PART_NAME_MAX_SIZE]; |
| AvbSlotVerifyResult ret; |
| AvbIOResult io_ret; |
| size_t vbmeta_offset; |
| size_t vbmeta_size; |
| uint8_t* vbmeta_buf = NULL; |
| size_t vbmeta_num_read; |
| AvbVBMetaVerifyResult vbmeta_ret; |
| const uint8_t* pk_data; |
| size_t pk_len; |
| AvbVBMetaImageHeader vbmeta_header; |
| uint64_t stored_rollback_index; |
| const AvbDescriptor** descriptors = NULL; |
| size_t num_descriptors; |
| size_t n; |
| bool is_main_vbmeta; |
| bool is_vbmeta_partition; |
| AvbVBMetaData* vbmeta_image_data = NULL; |
| |
| ret = AVB_SLOT_VERIFY_RESULT_OK; |
| |
| avb_assert(slot_data != NULL); |
| |
| /* Since we allow top-level vbmeta in 'boot', use |
| * rollback_index_location to determine whether we're the main |
| * vbmeta struct. |
| */ |
| is_main_vbmeta = (rollback_index_location == 0); |
| is_vbmeta_partition = (avb_strcmp(partition_name, "vbmeta") == 0); |
| |
| if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) { |
| avb_error("Partition name is not valid UTF-8.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| /* Construct full partition name. */ |
| if (!avb_str_concat(full_partition_name, |
| sizeof full_partition_name, |
| partition_name, |
| partition_name_len, |
| ab_suffix, |
| avb_strlen(ab_suffix))) { |
| avb_error("Partition name and suffix does not fit.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| avb_debugv("Loading vbmeta struct from partition '", |
| full_partition_name, |
| "'.\n", |
| NULL); |
| |
| /* If we're loading from the main vbmeta partition, the vbmeta |
| * struct is in the beginning. Otherwise we have to locate it via a |
| * footer. |
| */ |
| if (is_vbmeta_partition) { |
| vbmeta_offset = 0; |
| vbmeta_size = VBMETA_MAX_SIZE; |
| } else { |
| uint8_t footer_buf[AVB_FOOTER_SIZE]; |
| size_t footer_num_read; |
| AvbFooter footer; |
| |
| io_ret = ops->read_from_partition(ops, |
| full_partition_name, |
| -AVB_FOOTER_SIZE, |
| AVB_FOOTER_SIZE, |
| footer_buf, |
| &footer_num_read); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(full_partition_name, ": Error loading footer.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| goto out; |
| } |
| avb_assert(footer_num_read == AVB_FOOTER_SIZE); |
| |
| if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf, |
| &footer)) { |
| avb_errorv(full_partition_name, ": Error validating footer.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| /* Basic footer sanity check since the data is untrusted. */ |
| if (footer.vbmeta_size > VBMETA_MAX_SIZE) { |
| avb_errorv( |
| full_partition_name, ": Invalid vbmeta size in footer.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| vbmeta_offset = footer.vbmeta_offset; |
| vbmeta_size = footer.vbmeta_size; |
| } |
| |
| vbmeta_buf = avb_malloc(vbmeta_size); |
| if (vbmeta_buf == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| |
| io_ret = ops->read_from_partition(ops, |
| full_partition_name, |
| vbmeta_offset, |
| vbmeta_size, |
| vbmeta_buf, |
| &vbmeta_num_read); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| /* If we're looking for 'vbmeta' but there is no such partition, |
| * go try to get it from the boot partition instead. |
| */ |
| if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION && |
| is_vbmeta_partition) { |
| avb_debugv(full_partition_name, |
| ": No such partition. Trying 'boot' instead.\n", |
| NULL); |
| ret = load_and_verify_vbmeta(ops, |
| requested_partitions, |
| ab_suffix, |
| allow_verification_error, |
| 0 /* toplevel_vbmeta_flags */, |
| 0 /* rollback_index_location */, |
| "boot", |
| avb_strlen("boot"), |
| NULL /* expected_public_key */, |
| 0 /* expected_public_key_length */, |
| slot_data, |
| out_algorithm_type, |
| out_additional_cmdline_subst); |
| goto out; |
| } else { |
| avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| goto out; |
| } |
| } |
| avb_assert(vbmeta_num_read <= vbmeta_size); |
| |
| /* Check if the image is properly signed and get the public key used |
| * to sign the image. |
| */ |
| vbmeta_ret = |
| avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len); |
| switch (vbmeta_ret) { |
| case AVB_VBMETA_VERIFY_RESULT_OK: |
| avb_assert(pk_data != NULL && pk_len > 0); |
| break; |
| |
| case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED: |
| case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH: |
| case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH: |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; |
| avb_errorv(full_partition_name, |
| ": Error verifying vbmeta image: ", |
| avb_vbmeta_verify_result_to_string(vbmeta_ret), |
| "\n", |
| NULL); |
| if (!allow_verification_error) { |
| goto out; |
| } |
| break; |
| |
| case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER: |
| /* No way to continue this case. */ |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| avb_errorv(full_partition_name, |
| ": Error verifying vbmeta image: invalid vbmeta header\n", |
| NULL); |
| goto out; |
| |
| case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION: |
| /* No way to continue this case. */ |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION; |
| avb_errorv(full_partition_name, |
| ": Error verifying vbmeta image: unsupported AVB version\n", |
| NULL); |
| goto out; |
| } |
| |
| /* Byteswap the header. */ |
| avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf, |
| &vbmeta_header); |
| |
| /* If we're the toplevel, assign flags so they'll be passed down. */ |
| if (is_main_vbmeta) { |
| toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags; |
| } else { |
| if (vbmeta_header.flags != 0) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| avb_errorv(full_partition_name, |
| ": chained vbmeta image has non-zero flags\n", |
| NULL); |
| goto out; |
| } |
| } |
| |
| /* Check if key used to make signature matches what is expected. */ |
| if (pk_data != NULL) { |
| if (expected_public_key != NULL) { |
| avb_assert(!is_main_vbmeta); |
| if (expected_public_key_length != pk_len || |
| avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) { |
| avb_errorv(full_partition_name, |
| ": Public key used to sign data does not match key in chain " |
| "partition descriptor.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; |
| if (!allow_verification_error) { |
| goto out; |
| } |
| } |
| } else { |
| bool key_is_trusted = false; |
| const uint8_t* pk_metadata = NULL; |
| size_t pk_metadata_len = 0; |
| |
| if (vbmeta_header.public_key_metadata_size > 0) { |
| pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) + |
| vbmeta_header.authentication_data_block_size + |
| vbmeta_header.public_key_metadata_offset; |
| pk_metadata_len = vbmeta_header.public_key_metadata_size; |
| } |
| |
| avb_assert(is_main_vbmeta); |
| io_ret = ops->validate_vbmeta_public_key( |
| ops, pk_data, pk_len, pk_metadata, pk_metadata_len, &key_is_trusted); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(full_partition_name, |
| ": Error while checking public key used to sign data.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| goto out; |
| } |
| if (!key_is_trusted) { |
| avb_errorv(full_partition_name, |
| ": Public key used to sign data rejected.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; |
| if (!allow_verification_error) { |
| goto out; |
| } |
| } |
| } |
| } |
| |
| /* Check rollback index. */ |
| io_ret = ops->read_rollback_index( |
| ops, rollback_index_location, &stored_rollback_index); |
| if (io_ret == AVB_IO_RESULT_ERROR_OOM) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } else if (io_ret != AVB_IO_RESULT_OK) { |
| avb_errorv(full_partition_name, |
| ": Error getting rollback index for location.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; |
| goto out; |
| } |
| if (vbmeta_header.rollback_index < stored_rollback_index) { |
| avb_errorv( |
| full_partition_name, |
| ": Image rollback index is less than the stored rollback index.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX; |
| if (!allow_verification_error) { |
| goto out; |
| } |
| } |
| |
| /* Copy vbmeta to vbmeta_images before recursing. */ |
| if (is_main_vbmeta) { |
| avb_assert(slot_data->num_vbmeta_images == 0); |
| } else { |
| avb_assert(slot_data->num_vbmeta_images > 0); |
| } |
| if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) { |
| avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++]; |
| vbmeta_image_data->partition_name = avb_strdup(partition_name); |
| vbmeta_image_data->vbmeta_data = vbmeta_buf; |
| /* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long |
| * and this includes data past the end of the image. Pass the |
| * actual size of the vbmeta image. Also, no need to use |
| * avb_safe_add() since the header has already been verified. |
| */ |
| vbmeta_image_data->vbmeta_size = |
| sizeof(AvbVBMetaImageHeader) + |
| vbmeta_header.authentication_data_block_size + |
| vbmeta_header.auxiliary_data_block_size; |
| vbmeta_image_data->verify_result = vbmeta_ret; |
| |
| /* If verification has been disabled by setting a bit in the image, |
| * we're done... except that we need to load the entirety of the |
| * requested partitions. |
| */ |
| if (vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) { |
| AvbSlotVerifyResult sub_ret; |
| avb_debugv( |
| full_partition_name, ": VERIFICATION_DISABLED bit is set.\n", NULL); |
| /* If load_requested_partitions() fail it is always a fatal |
| * failure (e.g. ERROR_INVALID_ARGUMENT, ERROR_OOM, etc.) rather |
| * than recoverable (e.g. one where result_should_continue() |
| * returns true) and we want to convey that error. |
| */ |
| sub_ret = load_requested_partitions( |
| ops, requested_partitions, ab_suffix, slot_data); |
| if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| ret = sub_ret; |
| } |
| goto out; |
| } |
| |
| /* Now go through all descriptors and take the appropriate action: |
| * |
| * - hash descriptor: Load data from partition, calculate hash, and |
| * checks that it matches what's in the hash descriptor. |
| * |
| * - hashtree descriptor: Do nothing since verification happens |
| * on-the-fly from within the OS. (Unless the descriptor uses a |
| * persistent digest, in which case we need to find it). |
| * |
| * - chained partition descriptor: Load the footer, load the vbmeta |
| * image, verify vbmeta image (includes rollback checks, hash |
| * checks, bail on chained partitions). |
| */ |
| descriptors = |
| avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors); |
| for (n = 0; n < num_descriptors; n++) { |
| AvbDescriptor desc; |
| |
| if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) { |
| avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| switch (desc.tag) { |
| case AVB_DESCRIPTOR_TAG_HASH: { |
| AvbSlotVerifyResult sub_ret; |
| sub_ret = load_and_verify_hash_partition(ops, |
| requested_partitions, |
| ab_suffix, |
| allow_verification_error, |
| descriptors[n], |
| slot_data); |
| if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| ret = sub_ret; |
| if (!allow_verification_error || !result_should_continue(ret)) { |
| goto out; |
| } |
| } |
| } break; |
| |
| case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: { |
| AvbSlotVerifyResult sub_ret; |
| AvbChainPartitionDescriptor chain_desc; |
| const uint8_t* chain_partition_name; |
| const uint8_t* chain_public_key; |
| |
| /* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */ |
| if (!is_main_vbmeta) { |
| avb_errorv(full_partition_name, |
| ": Encountered chain descriptor not in main image.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| if (!avb_chain_partition_descriptor_validate_and_byteswap( |
| (AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) { |
| avb_errorv(full_partition_name, |
| ": Chain partition descriptor is invalid.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| if (chain_desc.rollback_index_location == 0) { |
| avb_errorv(full_partition_name, |
| ": Chain partition has invalid " |
| "rollback_index_location field.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| chain_partition_name = ((const uint8_t*)descriptors[n]) + |
| sizeof(AvbChainPartitionDescriptor); |
| chain_public_key = chain_partition_name + chain_desc.partition_name_len; |
| |
| sub_ret = |
| load_and_verify_vbmeta(ops, |
| requested_partitions, |
| ab_suffix, |
| allow_verification_error, |
| toplevel_vbmeta_flags, |
| chain_desc.rollback_index_location, |
| (const char*)chain_partition_name, |
| chain_desc.partition_name_len, |
| chain_public_key, |
| chain_desc.public_key_len, |
| slot_data, |
| NULL, /* out_algorithm_type */ |
| NULL /* out_additional_cmdline_subst */); |
| if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| ret = sub_ret; |
| if (!result_should_continue(ret)) { |
| goto out; |
| } |
| } |
| } break; |
| |
| case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: { |
| const uint8_t* kernel_cmdline; |
| AvbKernelCmdlineDescriptor kernel_cmdline_desc; |
| bool apply_cmdline; |
| |
| if (!avb_kernel_cmdline_descriptor_validate_and_byteswap( |
| (AvbKernelCmdlineDescriptor*)descriptors[n], |
| &kernel_cmdline_desc)) { |
| avb_errorv(full_partition_name, |
| ": Kernel cmdline descriptor is invalid.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| kernel_cmdline = ((const uint8_t*)descriptors[n]) + |
| sizeof(AvbKernelCmdlineDescriptor); |
| |
| if (!avb_validate_utf8(kernel_cmdline, |
| kernel_cmdline_desc.kernel_cmdline_length)) { |
| avb_errorv(full_partition_name, |
| ": Kernel cmdline is not valid UTF-8.\n", |
| NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| /* Compare the flags for top-level VBMeta struct with flags in |
| * the command-line descriptor so command-line snippets only |
| * intended for a certain mode (dm-verity enabled/disabled) |
| * are skipped if applicable. |
| */ |
| apply_cmdline = true; |
| if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) { |
| if (kernel_cmdline_desc.flags & |
| AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) { |
| apply_cmdline = false; |
| } |
| } else { |
| if (kernel_cmdline_desc.flags & |
| AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) { |
| apply_cmdline = false; |
| } |
| } |
| |
| if (apply_cmdline) { |
| if (slot_data->cmdline == NULL) { |
| slot_data->cmdline = |
| avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1); |
| if (slot_data->cmdline == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| avb_memcpy(slot_data->cmdline, |
| kernel_cmdline, |
| kernel_cmdline_desc.kernel_cmdline_length); |
| } else { |
| /* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */ |
| size_t orig_size = avb_strlen(slot_data->cmdline); |
| size_t new_size = |
| orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1; |
| char* new_cmdline = avb_calloc(new_size); |
| if (new_cmdline == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto out; |
| } |
| avb_memcpy(new_cmdline, slot_data->cmdline, orig_size); |
| new_cmdline[orig_size] = ' '; |
| avb_memcpy(new_cmdline + orig_size + 1, |
| kernel_cmdline, |
| kernel_cmdline_desc.kernel_cmdline_length); |
| avb_free(slot_data->cmdline); |
| slot_data->cmdline = new_cmdline; |
| } |
| } |
| } break; |
| |
| case AVB_DESCRIPTOR_TAG_HASHTREE: { |
| AvbHashtreeDescriptor hashtree_desc; |
| |
| if (!avb_hashtree_descriptor_validate_and_byteswap( |
| (AvbHashtreeDescriptor*)descriptors[n], &hashtree_desc)) { |
| avb_errorv( |
| full_partition_name, ": Hashtree descriptor is invalid.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| /* We only need to continue when there is no digest in the descriptor. |
| * This is because the only processing here is to find the digest and |
| * make it available on the kernel command line. |
| */ |
| if (hashtree_desc.root_digest_len == 0) { |
| char part_name[AVB_PART_NAME_MAX_SIZE]; |
| size_t digest_len = 0; |
| uint8_t digest_buf[AVB_SHA512_DIGEST_SIZE]; |
| const uint8_t* desc_partition_name = |
| ((const uint8_t*)descriptors[n]) + sizeof(AvbHashtreeDescriptor); |
| |
| if (!avb_validate_utf8(desc_partition_name, |
| hashtree_desc.partition_name_len)) { |
| avb_error("Partition name is not valid UTF-8.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| /* No ab_suffix for partitions without a digest in the descriptor |
| * because these partitions hold data unique to this device and are |
| * not updated using an A/B scheme. |
| */ |
| if ((hashtree_desc.flags & |
| AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) == 0 && |
| avb_strlen(ab_suffix) != 0) { |
| avb_error("Cannot use A/B with a persistent root digest.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| if (hashtree_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) { |
| avb_error("Partition name does not fit.\n"); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| avb_memcpy( |
| part_name, desc_partition_name, hashtree_desc.partition_name_len); |
| part_name[hashtree_desc.partition_name_len] = '\0'; |
| |
| /* Determine the expected digest size from the hash algorithm. */ |
| if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, "sha1") == |
| 0) { |
| digest_len = AVB_SHA1_DIGEST_SIZE; |
| } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, |
| "sha256") == 0) { |
| digest_len = AVB_SHA256_DIGEST_SIZE; |
| } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, |
| "sha512") == 0) { |
| digest_len = AVB_SHA512_DIGEST_SIZE; |
| } else { |
| avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| ret = read_persistent_digest(ops, part_name, digest_len, digest_buf); |
| if (ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| goto out; |
| } |
| |
| if (out_additional_cmdline_subst) { |
| ret = |
| avb_add_root_digest_substitution(part_name, |
| digest_buf, |
| digest_len, |
| out_additional_cmdline_subst); |
| if (ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| goto out; |
| } |
| } |
| } |
| } break; |
| |
| case AVB_DESCRIPTOR_TAG_PROPERTY: |
| /* Do nothing. */ |
| break; |
| } |
| } |
| |
| if (rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) { |
| avb_errorv( |
| full_partition_name, ": Invalid rollback_index_location.\n", NULL); |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; |
| goto out; |
| } |
| |
| slot_data->rollback_indexes[rollback_index_location] = |
| vbmeta_header.rollback_index; |
| |
| if (out_algorithm_type != NULL) { |
| *out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type; |
| } |
| |
| out: |
| /* If |vbmeta_image_data| isn't NULL it means that it adopted |
| * |vbmeta_buf| so in that case don't free it here. |
| */ |
| if (vbmeta_image_data == NULL) { |
| if (vbmeta_buf != NULL) { |
| avb_free(vbmeta_buf); |
| } |
| } |
| if (descriptors != NULL) { |
| avb_free(descriptors); |
| } |
| return ret; |
| } |
| |
| AvbSlotVerifyResult avb_slot_verify(AvbOps* ops, |
| const char* const* requested_partitions, |
| const char* ab_suffix, |
| AvbSlotVerifyFlags flags, |
| AvbHashtreeErrorMode hashtree_error_mode, |
| AvbSlotVerifyData** out_data) { |
| AvbSlotVerifyResult ret; |
| AvbSlotVerifyData* slot_data = NULL; |
| AvbAlgorithmType algorithm_type = AVB_ALGORITHM_TYPE_NONE; |
| bool using_boot_for_vbmeta = false; |
| AvbVBMetaImageHeader toplevel_vbmeta; |
| bool allow_verification_error = |
| (flags & AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR); |
| AvbCmdlineSubstList* additional_cmdline_subst = NULL; |
| |
| /* Fail early if we're missing the AvbOps needed for slot verification. |
| * |
| * For now, handle get_size_of_partition() not being implemented. In |
| * a later release we may change that. |
| */ |
| avb_assert(ops->read_is_device_unlocked != NULL); |
| avb_assert(ops->read_from_partition != NULL); |
| avb_assert(ops->validate_vbmeta_public_key != NULL); |
| avb_assert(ops->read_rollback_index != NULL); |
| avb_assert(ops->get_unique_guid_for_partition != NULL); |
| |
| if (out_data != NULL) { |
| *out_data = NULL; |
| } |
| |
| /* Allowing dm-verity errors defeats the purpose of verified boot so |
| * only allow this if set up to allow verification errors |
| * (e.g. typically only UNLOCKED mode). |
| */ |
| if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_LOGGING && |
| !allow_verification_error) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT; |
| goto fail; |
| } |
| |
| slot_data = avb_calloc(sizeof(AvbSlotVerifyData)); |
| if (slot_data == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| slot_data->vbmeta_images = |
| avb_calloc(sizeof(AvbVBMetaData) * MAX_NUMBER_OF_VBMETA_IMAGES); |
| if (slot_data->vbmeta_images == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| slot_data->loaded_partitions = |
| avb_calloc(sizeof(AvbPartitionData) * MAX_NUMBER_OF_LOADED_PARTITIONS); |
| if (slot_data->loaded_partitions == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| |
| additional_cmdline_subst = avb_new_cmdline_subst_list(); |
| if (additional_cmdline_subst == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| |
| ret = load_and_verify_vbmeta(ops, |
| requested_partitions, |
| ab_suffix, |
| allow_verification_error, |
| 0 /* toplevel_vbmeta_flags */, |
| 0 /* rollback_index_location */, |
| "vbmeta", |
| avb_strlen("vbmeta"), |
| NULL /* expected_public_key */, |
| 0 /* expected_public_key_length */, |
| slot_data, |
| &algorithm_type, |
| additional_cmdline_subst); |
| if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| goto fail; |
| } |
| |
| /* If things check out, mangle the kernel command-line as needed. */ |
| if (result_should_continue(ret)) { |
| if (avb_strcmp(slot_data->vbmeta_images[0].partition_name, "vbmeta") != 0) { |
| avb_assert( |
| avb_strcmp(slot_data->vbmeta_images[0].partition_name, "boot") == 0); |
| using_boot_for_vbmeta = true; |
| } |
| |
| /* Byteswap top-level vbmeta header since we'll need it below. */ |
| avb_vbmeta_image_header_to_host_byte_order( |
| (const AvbVBMetaImageHeader*)slot_data->vbmeta_images[0].vbmeta_data, |
| &toplevel_vbmeta); |
| |
| /* Fill in |ab_suffix| field. */ |
| slot_data->ab_suffix = avb_strdup(ab_suffix); |
| if (slot_data->ab_suffix == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| |
| /* If verification is disabled, we are done ... we specifically |
| * don't want to add any androidboot.* options since verification |
| * is disabled. |
| */ |
| if (toplevel_vbmeta.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) { |
| /* Since verification is disabled we didn't process any |
| * descriptors and thus there's no cmdline... so set root= such |
| * that the system partition is mounted. |
| */ |
| avb_assert(slot_data->cmdline == NULL); |
| slot_data->cmdline = |
| avb_strdup("root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)"); |
| if (slot_data->cmdline == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| } else { |
| /* Add options - any failure in avb_append_options() is either an |
| * I/O or OOM error. |
| */ |
| AvbSlotVerifyResult sub_ret = avb_append_options(ops, |
| slot_data, |
| &toplevel_vbmeta, |
| algorithm_type, |
| hashtree_error_mode); |
| if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { |
| ret = sub_ret; |
| goto fail; |
| } |
| } |
| |
| /* Substitute $(ANDROID_SYSTEM_PARTUUID) and friends. */ |
| if (slot_data->cmdline != NULL) { |
| char* new_cmdline; |
| new_cmdline = avb_sub_cmdline(ops, |
| slot_data->cmdline, |
| ab_suffix, |
| using_boot_for_vbmeta, |
| additional_cmdline_subst); |
| if (new_cmdline != slot_data->cmdline) { |
| if (new_cmdline == NULL) { |
| ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; |
| goto fail; |
| } |
| avb_free(slot_data->cmdline); |
| slot_data->cmdline = new_cmdline; |
| } |
| } |
| |
| if (out_data != NULL) { |
| *out_data = slot_data; |
| } else { |
| avb_slot_verify_data_free(slot_data); |
| } |
| } |
| |
| avb_free_cmdline_subst_list(additional_cmdline_subst); |
| additional_cmdline_subst = NULL; |
| |
| if (!allow_verification_error) { |
| avb_assert(ret == AVB_SLOT_VERIFY_RESULT_OK); |
| } |
| |
| return ret; |
| |
| fail: |
| if (slot_data != NULL) { |
| avb_slot_verify_data_free(slot_data); |
| } |
| if (additional_cmdline_subst != NULL) { |
| avb_free_cmdline_subst_list(additional_cmdline_subst); |
| } |
| return ret; |
| } |
| |
| void avb_slot_verify_data_free(AvbSlotVerifyData* data) { |
| if (data->ab_suffix != NULL) { |
| avb_free(data->ab_suffix); |
| } |
| if (data->cmdline != NULL) { |
| avb_free(data->cmdline); |
| } |
| if (data->vbmeta_images != NULL) { |
| size_t n; |
| for (n = 0; n < data->num_vbmeta_images; n++) { |
| AvbVBMetaData* vbmeta_image = &data->vbmeta_images[n]; |
| if (vbmeta_image->partition_name != NULL) { |
| avb_free(vbmeta_image->partition_name); |
| } |
| if (vbmeta_image->vbmeta_data != NULL) { |
| avb_free(vbmeta_image->vbmeta_data); |
| } |
| } |
| avb_free(data->vbmeta_images); |
| } |
| if (data->loaded_partitions != NULL) { |
| size_t n; |
| for (n = 0; n < data->num_loaded_partitions; n++) { |
| AvbPartitionData* loaded_partition = &data->loaded_partitions[n]; |
| if (loaded_partition->partition_name != NULL) { |
| avb_free(loaded_partition->partition_name); |
| } |
| if (loaded_partition->data != NULL && !loaded_partition->preloaded) { |
| avb_free(loaded_partition->data); |
| } |
| } |
| avb_free(data->loaded_partitions); |
| } |
| avb_free(data); |
| } |
| |
| const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result) { |
| const char* ret = NULL; |
| |
| switch (result) { |
| case AVB_SLOT_VERIFY_RESULT_OK: |
| ret = "OK"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: |
| ret = "ERROR_OOM"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_IO: |
| ret = "ERROR_IO"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: |
| ret = "ERROR_VERIFICATION"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: |
| ret = "ERROR_ROLLBACK_INDEX"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: |
| ret = "ERROR_PUBLIC_KEY_REJECTED"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: |
| ret = "ERROR_INVALID_METADATA"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: |
| ret = "ERROR_UNSUPPORTED_VERSION"; |
| break; |
| case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT: |
| ret = "ERROR_INVALID_ARGUMENT"; |
| break; |
| /* Do not add a 'default:' case here because of -Wswitch. */ |
| } |
| |
| if (ret == NULL) { |
| avb_error("Unknown AvbSlotVerifyResult value.\n"); |
| ret = "(unknown)"; |
| } |
| |
| return ret; |
| } |
| |
| void avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData* data, |
| AvbDigestType digest_type, |
| uint8_t* out_digest) { |
| bool ret = false; |
| size_t n; |
| |
| switch (digest_type) { |
| case AVB_DIGEST_TYPE_SHA256: { |
| AvbSHA256Ctx ctx; |
| avb_sha256_init(&ctx); |
| for (n = 0; n < data->num_vbmeta_images; n++) { |
| avb_sha256_update(&ctx, |
| data->vbmeta_images[n].vbmeta_data, |
| data->vbmeta_images[n].vbmeta_size); |
| } |
| avb_memcpy(out_digest, avb_sha256_final(&ctx), AVB_SHA256_DIGEST_SIZE); |
| ret = true; |
| } break; |
| |
| case AVB_DIGEST_TYPE_SHA512: { |
| AvbSHA512Ctx ctx; |
| avb_sha512_init(&ctx); |
| for (n = 0; n < data->num_vbmeta_images; n++) { |
| avb_sha512_update(&ctx, |
| data->vbmeta_images[n].vbmeta_data, |
| data->vbmeta_images[n].vbmeta_size); |
| } |
| avb_memcpy(out_digest, avb_sha512_final(&ctx), AVB_SHA512_DIGEST_SIZE); |
| ret = true; |
| } break; |
| |
| /* Do not add a 'default:' case here because of -Wswitch. */ |
| } |
| |
| if (!ret) { |
| avb_fatal("Unknown digest type"); |
| } |
| } |
