void avb_free_cmdline_subst_list(AvbCmdlineSubstList* cmdline_subst) {
size_t i;
for (i = 0; i < cmdline_subst->size; ++i) {
avb_free(cmdline_subst->tokens[i]);
avb_free(cmdline_subst->values[i]);
}
cmdline_subst->size = 0;
avb_free(cmdline_subst);
}
AvbSlotVerifyResult avb_add_root_digest_substitution(
const char* part_name,
const uint8_t* digest,
size_t digest_size,
AvbCmdlineSubstList* out_cmdline_subst) {
const char* kDigestSubPrefix = "$(AVB_";
const char* kDigestSubSuffix = "_ROOT_DIGEST)";
size_t part_name_len = avb_strlen(part_name);
size_t list_index = out_cmdline_subst->size;
avb_assert(part_name_len < AVB_PART_NAME_MAX_SIZE);
avb_assert(digest_size <= AVB_SHA512_DIGEST_SIZE);
if (part_name_len >= AVB_PART_NAME_MAX_SIZE ||
digest_size > AVB_SHA512_DIGEST_SIZE) {
return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
}
if (out_cmdline_subst->size >= AVB_MAX_NUM_CMDLINE_SUBST) {
/* The list is full. Currently dynamic growth of this list is not supported.
*/
return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
}
/* Construct the token to replace in the command line based on the partition
* name. For partition 'foo', this will be '$(AVB_FOO_ROOT_DIGEST)'.
*/
out_cmdline_subst->tokens[list_index] =
avb_strdupv(kDigestSubPrefix, part_name, kDigestSubSuffix, NULL);
if (out_cmdline_subst->tokens[list_index] == NULL) {
goto fail;
}
avb_uppercase(out_cmdline_subst->tokens[list_index]);
/* The digest value is hex encoded when inserted in the command line. */
out_cmdline_subst->values[list_index] = avb_bin2hex(digest, digest_size);
if (out_cmdline_subst->values[list_index] == NULL) {
goto fail;
}
out_cmdline_subst->size++;
return AVB_SLOT_VERIFY_RESULT_OK;
fail:
if (out_cmdline_subst->tokens[list_index]) {
avb_free(out_cmdline_subst->tokens[list_index]);
}
if (out_cmdline_subst->values[list_index]) {
avb_free(out_cmdline_subst->values[list_index]);
}
return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
}
static int cmdline_append_option(AvbSlotVerifyData* slot_data,
const char* key,
const char* value) {
size_t offset, key_len, value_len;
char* new_cmdline;
key_len = avb_strlen(key);
value_len = avb_strlen(value);
offset = 0;
if (slot_data->cmdline != NULL) {
offset = avb_strlen(slot_data->cmdline);
if (offset > 0) {
offset += 1;
}
}
new_cmdline = avb_calloc(offset + key_len + value_len + 2);
if (new_cmdline == NULL) {
return 0;
}
if (offset > 0) {
avb_memcpy(new_cmdline, slot_data->cmdline, offset - 1);
new_cmdline[offset - 1] = ' ';
}
avb_memcpy(new_cmdline + offset, key, key_len);
new_cmdline[offset + key_len] = '=';
avb_memcpy(new_cmdline + offset + key_len + 1, value, value_len);
if (slot_data->cmdline != NULL) {
avb_free(slot_data->cmdline);
}
slot_data->cmdline = new_cmdline;
return 1;
}
void avb_ops_free(AvbOps *ops)
{
struct AvbOpsData *ops_data;
if (ops)
return;
ops_data = ops->user_data;
if (ops_data)
avb_free(ops_data);
}
static int cmdline_append_hex(AvbSlotVerifyData* slot_data,
const char* key,
const uint8_t* data,
size_t data_len) {
int ret;
char* hex_data = avb_bin2hex(data, data_len);
if (hex_data == NULL) {
return 0;
}
ret = cmdline_append_option(slot_data, key, hex_data);
avb_free(hex_data);
return ret;
}
AvbSlotVerifyResult avb_append_options(
AvbOps* ops,
AvbSlotVerifyData* slot_data,
AvbVBMetaImageHeader* toplevel_vbmeta,
AvbAlgorithmType algorithm_type,
AvbHashtreeErrorMode hashtree_error_mode) {
AvbSlotVerifyResult ret;
const char* verity_mode;
bool is_device_unlocked;
AvbIOResult io_ret;
/* Add androidboot.vbmeta.device option. */
if (!cmdline_append_option(slot_data,
"androidboot.vbmeta.device",
"PARTUUID=$(ANDROID_VBMETA_PARTUUID)")) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
/* Add androidboot.vbmeta.avb_version option. */
if (!cmdline_append_version(slot_data,
"androidboot.vbmeta.avb_version",
AVB_VERSION_MAJOR,
AVB_VERSION_MINOR)) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
/* Set androidboot.avb.device_state to "locked" or "unlocked". */
io_ret = ops->read_is_device_unlocked(ops, &is_device_unlocked);
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_error("Error getting device state.\n");
ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
goto out;
}
if (!cmdline_append_option(slot_data,
"androidboot.vbmeta.device_state",
is_device_unlocked ? "unlocked" : "locked")) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
/* Set androidboot.vbmeta.{hash_alg, size, digest} - use same hash
* function as is used to sign vbmeta.
*/
switch (algorithm_type) {
/* Explicit fallthrough. */
case AVB_ALGORITHM_TYPE_NONE:
case AVB_ALGORITHM_TYPE_SHA256_RSA2048:
case AVB_ALGORITHM_TYPE_SHA256_RSA4096:
case AVB_ALGORITHM_TYPE_SHA256_RSA8192: {
size_t n, total_size = 0;
uint8_t vbmeta_digest[AVB_SHA256_DIGEST_SIZE];
avb_slot_verify_data_calculate_vbmeta_digest(
slot_data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest);
for (n = 0; n < slot_data->num_vbmeta_images; n++) {
total_size += slot_data->vbmeta_images[n].vbmeta_size;
}
if (!cmdline_append_option(
slot_data, "androidboot.vbmeta.hash_alg", "sha256") ||
!cmdline_append_uint64_base10(
slot_data, "androidboot.vbmeta.size", total_size) ||
!cmdline_append_hex(slot_data,
"androidboot.vbmeta.digest",
vbmeta_digest,
AVB_SHA256_DIGEST_SIZE)) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
} break;
/* Explicit fallthrough. */
case AVB_ALGORITHM_TYPE_SHA512_RSA2048:
case AVB_ALGORITHM_TYPE_SHA512_RSA4096:
case AVB_ALGORITHM_TYPE_SHA512_RSA8192: {
size_t n, total_size = 0;
uint8_t vbmeta_digest[AVB_SHA512_DIGEST_SIZE];
avb_slot_verify_data_calculate_vbmeta_digest(
slot_data, AVB_DIGEST_TYPE_SHA512, vbmeta_digest);
for (n = 0; n < slot_data->num_vbmeta_images; n++) {
total_size += slot_data->vbmeta_images[n].vbmeta_size;
}
if (!cmdline_append_option(
slot_data, "androidboot.vbmeta.hash_alg", "sha512") ||
!cmdline_append_uint64_base10(
slot_data, "androidboot.vbmeta.size", total_size) ||
!cmdline_append_hex(slot_data,
"androidboot.vbmeta.digest",
vbmeta_digest,
AVB_SHA512_DIGEST_SIZE)) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
} break;
case _AVB_ALGORITHM_NUM_TYPES:
avb_assert_not_reached();
break;
}
/* Set androidboot.veritymode and androidboot.vbmeta.invalidate_on_error */
if (toplevel_vbmeta->flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) {
verity_mode = "disabled";
} else {
const char* dm_verity_mode;
char* new_ret;
switch (hashtree_error_mode) {
case AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE:
if (!cmdline_append_option(
slot_data, "androidboot.vbmeta.invalidate_on_error", "yes")) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
verity_mode = "enforcing";
dm_verity_mode = "restart_on_corruption";
break;
case AVB_HASHTREE_ERROR_MODE_RESTART:
verity_mode = "enforcing";
dm_verity_mode = "restart_on_corruption";
break;
case AVB_HASHTREE_ERROR_MODE_EIO:
verity_mode = "eio";
/* For now there's no option to specify the EIO mode. So
* just use 'ignore_zero_blocks' since that's already set
* and dm-verity-target.c supports specifying this multiple
* times.
*/
dm_verity_mode = "ignore_zero_blocks";
break;
case AVB_HASHTREE_ERROR_MODE_LOGGING:
verity_mode = "logging";
dm_verity_mode = "ignore_corruption";
break;
default:
ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT;
goto out;
}
new_ret = avb_replace(
slot_data->cmdline, "$(ANDROID_VERITY_MODE)", dm_verity_mode);
avb_free(slot_data->cmdline);
slot_data->cmdline = new_ret;
if (slot_data->cmdline == NULL) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
}
if (!cmdline_append_option(
slot_data, "androidboot.veritymode", verity_mode)) {
ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
goto out;
}
ret = AVB_SLOT_VERIFY_RESULT_OK;
out:
return ret;
}
/* Substitutes all variables (e.g. $(ANDROID_SYSTEM_PARTUUID)) with
* values. Returns NULL on OOM, otherwise the cmdline with values
* replaced.
*/
char* avb_sub_cmdline(AvbOps* ops,
const char* cmdline,
const char* ab_suffix,
bool using_boot_for_vbmeta,
const AvbCmdlineSubstList* additional_substitutions) {
const char* part_name_str[NUM_GUIDS] = {"system", "boot", "vbmeta"};
const char* replace_str[NUM_GUIDS] = {"$(ANDROID_SYSTEM_PARTUUID)",
"$(ANDROID_BOOT_PARTUUID)",
"$(ANDROID_VBMETA_PARTUUID)"};
char* ret = NULL;
AvbIOResult io_ret;
size_t n;
/* Special-case for when the top-level vbmeta struct is in the boot
* partition.
*/
if (using_boot_for_vbmeta) {
part_name_str[2] = "boot";
}
/* Replace unique partition GUIDs */
for (n = 0; n < NUM_GUIDS; n++) {
char part_name[AVB_PART_NAME_MAX_SIZE];
char guid_buf[37];
if (!avb_str_concat(part_name,
sizeof part_name,
part_name_str[n],
avb_strlen(part_name_str[n]),
ab_suffix,
avb_strlen(ab_suffix))) {
avb_error("Partition name and suffix does not fit.\n");
goto fail;
}
io_ret = ops->get_unique_guid_for_partition(
ops, part_name, guid_buf, sizeof guid_buf);
if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
goto fail;
} else if (io_ret != AVB_IO_RESULT_OK) {
avb_error("Error getting unique GUID for partition.\n");
goto fail;
}
if (ret == NULL) {
ret = avb_replace(cmdline, replace_str[n], guid_buf);
} else {
char* new_ret = avb_replace(ret, replace_str[n], guid_buf);
avb_free(ret);
ret = new_ret;
}
if (ret == NULL) {
goto fail;
}
}
avb_assert(ret != NULL);
/* Replace any additional substitutions. */
if (additional_substitutions != NULL) {
for (n = 0; n < additional_substitutions->size; ++n) {
char* new_ret = avb_replace(ret,
additional_substitutions->tokens[n],
additional_substitutions->values[n]);
avb_free(ret);
ret = new_ret;
if (ret == NULL) {
goto fail;
}
}
}
return ret;
fail:
if (ret != NULL) {
avb_free(ret);
}
return NULL;
}