| // SPDX-License-Identifier: MIT |
| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| */ |
| |
| #include "avb_cmdline.h" |
| #include "avb_sha.h" |
| #include "avb_util.h" |
| #include "avb_version.h" |
| |
| #define NUM_GUIDS 3 |
| |
| /* 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; |
| } |
| |
| 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; |
| } |
| |
| #define AVB_MAX_DIGITS_UINT64 32 |
| |
| /* Writes |value| to |digits| in base 10 followed by a NUL byte. |
| * Returns number of characters written excluding the NUL byte. |
| */ |
| static size_t uint64_to_base10(uint64_t value, |
| char digits[AVB_MAX_DIGITS_UINT64]) { |
| char rev_digits[AVB_MAX_DIGITS_UINT64]; |
| size_t n, num_digits; |
| |
| for (num_digits = 0; num_digits < AVB_MAX_DIGITS_UINT64 - 1;) { |
| rev_digits[num_digits++] = avb_div_by_10(&value) + '0'; |
| if (value == 0) { |
| break; |
| } |
| } |
| |
| for (n = 0; n < num_digits; n++) { |
| digits[n] = rev_digits[num_digits - 1 - n]; |
| } |
| digits[n] = '\0'; |
| return n; |
| } |
| |
| static int cmdline_append_version(AvbSlotVerifyData* slot_data, |
| const char* key, |
| uint64_t major_version, |
| uint64_t minor_version) { |
| char major_digits[AVB_MAX_DIGITS_UINT64]; |
| char minor_digits[AVB_MAX_DIGITS_UINT64]; |
| char combined[AVB_MAX_DIGITS_UINT64 * 2 + 1]; |
| size_t num_major_digits, num_minor_digits; |
| |
| num_major_digits = uint64_to_base10(major_version, major_digits); |
| num_minor_digits = uint64_to_base10(minor_version, minor_digits); |
| avb_memcpy(combined, major_digits, num_major_digits); |
| combined[num_major_digits] = '.'; |
| avb_memcpy(combined + num_major_digits + 1, minor_digits, num_minor_digits); |
| combined[num_major_digits + 1 + num_minor_digits] = '\0'; |
| |
| return cmdline_append_option(slot_data, key, combined); |
| } |
| |
| static int cmdline_append_uint64_base10(AvbSlotVerifyData* slot_data, |
| const char* key, |
| uint64_t value) { |
| char digits[AVB_MAX_DIGITS_UINT64]; |
| uint64_to_base10(value, digits); |
| return cmdline_append_option(slot_data, key, digits); |
| } |
| |
| 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 = NULL; |
| 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 = NULL; |
| 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; |
| } |
| |
| AvbCmdlineSubstList* avb_new_cmdline_subst_list() { |
| return (AvbCmdlineSubstList*)avb_calloc(sizeof(AvbCmdlineSubstList)); |
| } |
| |
| 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; |
| } |
