/*
|
* Copyright (C) 2016 The Android Open Source Project
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy,
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* modify, merge, publish, distribute, sublicense, and/or sell copies
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* of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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|
#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"
|
|
/* 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 (!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) {
|
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);
|
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 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");
|
}
|
}
|
