/*
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* 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_cmdline.h"
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#include "avb_sha.h"
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#include "avb_util.h"
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#include "avb_version.h"
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#define NUM_GUIDS 3
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/* Substitutes all variables (e.g. $(ANDROID_SYSTEM_PARTUUID)) with
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* values. Returns NULL on OOM, otherwise the cmdline with values
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* replaced.
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*/
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char* avb_sub_cmdline(AvbOps* ops,
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const char* cmdline,
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const char* ab_suffix,
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bool using_boot_for_vbmeta,
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const AvbCmdlineSubstList* additional_substitutions) {
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const char* part_name_str[NUM_GUIDS] = {"system", "boot", "vbmeta"};
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const char* replace_str[NUM_GUIDS] = {"$(ANDROID_SYSTEM_PARTUUID)",
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"$(ANDROID_BOOT_PARTUUID)",
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"$(ANDROID_VBMETA_PARTUUID)"};
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char* ret = NULL;
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AvbIOResult io_ret;
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size_t n;
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/* Special-case for when the top-level vbmeta struct is in the boot
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* partition.
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*/
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if (using_boot_for_vbmeta) {
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part_name_str[2] = "boot";
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}
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/* Replace unique partition GUIDs */
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for (n = 0; n < NUM_GUIDS; n++) {
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char part_name[AVB_PART_NAME_MAX_SIZE];
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char guid_buf[37];
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if (!avb_str_concat(part_name,
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sizeof part_name,
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part_name_str[n],
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avb_strlen(part_name_str[n]),
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ab_suffix,
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avb_strlen(ab_suffix))) {
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avb_error("Partition name and suffix does not fit.\n");
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goto fail;
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}
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io_ret = ops->get_unique_guid_for_partition(
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ops, part_name, guid_buf, sizeof guid_buf);
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if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
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goto fail;
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} else if (io_ret != AVB_IO_RESULT_OK) {
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avb_error("Error getting unique GUID for partition.\n");
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goto fail;
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}
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if (ret == NULL) {
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ret = avb_replace(cmdline, replace_str[n], guid_buf);
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} else {
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char* new_ret = avb_replace(ret, replace_str[n], guid_buf);
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avb_free(ret);
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ret = new_ret;
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}
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if (ret == NULL) {
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goto fail;
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}
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}
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avb_assert(ret != NULL);
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/* Replace any additional substitutions. */
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if (additional_substitutions != NULL) {
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for (n = 0; n < additional_substitutions->size; ++n) {
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char* new_ret = avb_replace(ret,
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additional_substitutions->tokens[n],
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additional_substitutions->values[n]);
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avb_free(ret);
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ret = new_ret;
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if (ret == NULL) {
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goto fail;
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}
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}
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}
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return ret;
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fail:
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if (ret != NULL) {
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avb_free(ret);
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}
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return NULL;
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}
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static int cmdline_append_option(AvbSlotVerifyData* slot_data,
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const char* key,
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const char* value) {
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size_t offset, key_len, value_len;
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char* new_cmdline;
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key_len = avb_strlen(key);
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value_len = avb_strlen(value);
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offset = 0;
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if (slot_data->cmdline != NULL) {
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offset = avb_strlen(slot_data->cmdline);
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if (offset > 0) {
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offset += 1;
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}
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}
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new_cmdline = avb_calloc(offset + key_len + value_len + 2);
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if (new_cmdline == NULL) {
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return 0;
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}
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if (offset > 0) {
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avb_memcpy(new_cmdline, slot_data->cmdline, offset - 1);
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new_cmdline[offset - 1] = ' ';
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}
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avb_memcpy(new_cmdline + offset, key, key_len);
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new_cmdline[offset + key_len] = '=';
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avb_memcpy(new_cmdline + offset + key_len + 1, value, value_len);
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if (slot_data->cmdline != NULL) {
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avb_free(slot_data->cmdline);
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}
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slot_data->cmdline = new_cmdline;
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return 1;
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}
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#define AVB_MAX_DIGITS_UINT64 32
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/* Writes |value| to |digits| in base 10 followed by a NUL byte.
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* Returns number of characters written excluding the NUL byte.
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*/
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static size_t uint64_to_base10(uint64_t value,
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char digits[AVB_MAX_DIGITS_UINT64]) {
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char rev_digits[AVB_MAX_DIGITS_UINT64];
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size_t n, num_digits;
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for (num_digits = 0; num_digits < AVB_MAX_DIGITS_UINT64 - 1;) {
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rev_digits[num_digits++] = avb_div_by_10(&value) + '0';
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if (value == 0) {
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break;
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}
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}
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for (n = 0; n < num_digits; n++) {
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digits[n] = rev_digits[num_digits - 1 - n];
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}
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digits[n] = '\0';
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return n;
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}
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static int cmdline_append_version(AvbSlotVerifyData* slot_data,
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const char* key,
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uint64_t major_version,
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uint64_t minor_version) {
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char major_digits[AVB_MAX_DIGITS_UINT64];
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char minor_digits[AVB_MAX_DIGITS_UINT64];
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char combined[AVB_MAX_DIGITS_UINT64 * 2 + 1];
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size_t num_major_digits, num_minor_digits;
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num_major_digits = uint64_to_base10(major_version, major_digits);
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num_minor_digits = uint64_to_base10(minor_version, minor_digits);
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avb_memcpy(combined, major_digits, num_major_digits);
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combined[num_major_digits] = '.';
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avb_memcpy(combined + num_major_digits + 1, minor_digits, num_minor_digits);
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combined[num_major_digits + 1 + num_minor_digits] = '\0';
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return cmdline_append_option(slot_data, key, combined);
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}
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static int cmdline_append_uint64_base10(AvbSlotVerifyData* slot_data,
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const char* key,
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uint64_t value) {
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char digits[AVB_MAX_DIGITS_UINT64];
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uint64_to_base10(value, digits);
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return cmdline_append_option(slot_data, key, digits);
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}
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static int cmdline_append_hex(AvbSlotVerifyData* slot_data,
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const char* key,
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const uint8_t* data,
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size_t data_len) {
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int ret;
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char* hex_data = avb_bin2hex(data, data_len);
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if (hex_data == NULL) {
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return 0;
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}
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ret = cmdline_append_option(slot_data, key, hex_data);
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avb_free(hex_data);
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return ret;
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}
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AvbSlotVerifyResult avb_append_options(
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AvbOps* ops,
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AvbSlotVerifyData* slot_data,
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AvbVBMetaImageHeader* toplevel_vbmeta,
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AvbAlgorithmType algorithm_type,
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AvbHashtreeErrorMode hashtree_error_mode) {
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AvbSlotVerifyResult ret;
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const char* verity_mode;
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bool is_device_unlocked;
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AvbIOResult io_ret;
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/* Add androidboot.vbmeta.device option. */
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if (!cmdline_append_option(slot_data,
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"androidboot.vbmeta.device",
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"PARTUUID=$(ANDROID_VBMETA_PARTUUID)")) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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/* Add androidboot.vbmeta.avb_version option. */
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if (!cmdline_append_version(slot_data,
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"androidboot.vbmeta.avb_version",
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AVB_VERSION_MAJOR,
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AVB_VERSION_MINOR)) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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/* Set androidboot.avb.device_state to "locked" or "unlocked". */
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io_ret = ops->read_is_device_unlocked(ops, &is_device_unlocked);
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if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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} else if (io_ret != AVB_IO_RESULT_OK) {
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avb_error("Error getting device state.\n");
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
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goto out;
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}
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if (!cmdline_append_option(slot_data,
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"androidboot.vbmeta.device_state",
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is_device_unlocked ? "unlocked" : "locked")) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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/* Set androidboot.vbmeta.{hash_alg, size, digest} - use same hash
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* function as is used to sign vbmeta.
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*/
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switch (algorithm_type) {
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/* Explicit fallthrough. */
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case AVB_ALGORITHM_TYPE_NONE:
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case AVB_ALGORITHM_TYPE_SHA256_RSA2048:
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case AVB_ALGORITHM_TYPE_SHA256_RSA4096:
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case AVB_ALGORITHM_TYPE_SHA256_RSA8192: {
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size_t n, total_size = 0;
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uint8_t vbmeta_digest[AVB_SHA256_DIGEST_SIZE];
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avb_slot_verify_data_calculate_vbmeta_digest(
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slot_data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest);
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for (n = 0; n < slot_data->num_vbmeta_images; n++) {
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total_size += slot_data->vbmeta_images[n].vbmeta_size;
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}
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if (!cmdline_append_option(
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slot_data, "androidboot.vbmeta.hash_alg", "sha256") ||
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!cmdline_append_uint64_base10(
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slot_data, "androidboot.vbmeta.size", total_size) ||
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!cmdline_append_hex(slot_data,
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"androidboot.vbmeta.digest",
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vbmeta_digest,
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AVB_SHA256_DIGEST_SIZE)) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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} break;
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/* Explicit fallthrough. */
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case AVB_ALGORITHM_TYPE_SHA512_RSA2048:
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case AVB_ALGORITHM_TYPE_SHA512_RSA4096:
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case AVB_ALGORITHM_TYPE_SHA512_RSA8192: {
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size_t n, total_size = 0;
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uint8_t vbmeta_digest[AVB_SHA512_DIGEST_SIZE];
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avb_slot_verify_data_calculate_vbmeta_digest(
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slot_data, AVB_DIGEST_TYPE_SHA512, vbmeta_digest);
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for (n = 0; n < slot_data->num_vbmeta_images; n++) {
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total_size += slot_data->vbmeta_images[n].vbmeta_size;
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}
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if (!cmdline_append_option(
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slot_data, "androidboot.vbmeta.hash_alg", "sha512") ||
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!cmdline_append_uint64_base10(
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slot_data, "androidboot.vbmeta.size", total_size) ||
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!cmdline_append_hex(slot_data,
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"androidboot.vbmeta.digest",
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vbmeta_digest,
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AVB_SHA512_DIGEST_SIZE)) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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} break;
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case _AVB_ALGORITHM_NUM_TYPES:
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avb_assert_not_reached();
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break;
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}
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/* Set androidboot.veritymode and androidboot.vbmeta.invalidate_on_error */
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if (toplevel_vbmeta->flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) {
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verity_mode = "disabled";
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} else {
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const char* dm_verity_mode;
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char* new_ret;
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switch (hashtree_error_mode) {
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case AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE:
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if (!cmdline_append_option(
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slot_data, "androidboot.vbmeta.invalidate_on_error", "yes")) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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verity_mode = "enforcing";
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dm_verity_mode = "restart_on_corruption";
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break;
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case AVB_HASHTREE_ERROR_MODE_RESTART:
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verity_mode = "enforcing";
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dm_verity_mode = "restart_on_corruption";
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break;
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case AVB_HASHTREE_ERROR_MODE_EIO:
|
verity_mode = "eio";
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/* For now there's no option to specify the EIO mode. So
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* just use 'ignore_zero_blocks' since that's already set
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* and dm-verity-target.c supports specifying this multiple
|
* times.
|
*/
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dm_verity_mode = "ignore_zero_blocks";
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break;
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case AVB_HASHTREE_ERROR_MODE_LOGGING:
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verity_mode = "logging";
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dm_verity_mode = "ignore_corruption";
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break;
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}
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new_ret = avb_replace(
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slot_data->cmdline, "$(ANDROID_VERITY_MODE)", dm_verity_mode);
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avb_free(slot_data->cmdline);
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slot_data->cmdline = new_ret;
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if (slot_data->cmdline == NULL) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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}
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if (!cmdline_append_option(
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slot_data, "androidboot.veritymode", verity_mode)) {
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ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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goto out;
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}
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ret = AVB_SLOT_VERIFY_RESULT_OK;
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out:
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return ret;
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}
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AvbCmdlineSubstList* avb_new_cmdline_subst_list() {
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return (AvbCmdlineSubstList*)avb_calloc(sizeof(AvbCmdlineSubstList));
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}
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void avb_free_cmdline_subst_list(AvbCmdlineSubstList* cmdline_subst) {
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size_t i;
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for (i = 0; i < cmdline_subst->size; ++i) {
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avb_free(cmdline_subst->tokens[i]);
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avb_free(cmdline_subst->values[i]);
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}
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cmdline_subst->size = 0;
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avb_free(cmdline_subst);
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}
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AvbSlotVerifyResult avb_add_root_digest_substitution(
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const char* part_name,
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const uint8_t* digest,
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size_t digest_size,
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AvbCmdlineSubstList* out_cmdline_subst) {
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const char* kDigestSubPrefix = "$(AVB_";
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const char* kDigestSubSuffix = "_ROOT_DIGEST)";
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size_t part_name_len = avb_strlen(part_name);
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size_t list_index = out_cmdline_subst->size;
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avb_assert(part_name_len < AVB_PART_NAME_MAX_SIZE);
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avb_assert(digest_size <= AVB_SHA512_DIGEST_SIZE);
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if (part_name_len >= AVB_PART_NAME_MAX_SIZE ||
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digest_size > AVB_SHA512_DIGEST_SIZE) {
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return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
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}
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if (out_cmdline_subst->size >= AVB_MAX_NUM_CMDLINE_SUBST) {
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/* The list is full. Currently dynamic growth of this list is not supported.
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*/
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return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
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}
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/* Construct the token to replace in the command line based on the partition
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* name. For partition 'foo', this will be '$(AVB_FOO_ROOT_DIGEST)'.
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*/
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out_cmdline_subst->tokens[list_index] =
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avb_strdupv(kDigestSubPrefix, part_name, kDigestSubSuffix, NULL);
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if (out_cmdline_subst->tokens[list_index] == NULL) {
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goto fail;
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}
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avb_uppercase(out_cmdline_subst->tokens[list_index]);
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|
/* The digest value is hex encoded when inserted in the command line. */
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out_cmdline_subst->values[list_index] = avb_bin2hex(digest, digest_size);
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if (out_cmdline_subst->values[list_index] == NULL) {
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goto fail;
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}
|
|
out_cmdline_subst->size++;
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return AVB_SLOT_VERIFY_RESULT_OK;
|
|
fail:
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if (out_cmdline_subst->tokens[list_index]) {
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avb_free(out_cmdline_subst->tokens[list_index]);
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}
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if (out_cmdline_subst->values[list_index]) {
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avb_free(out_cmdline_subst->values[list_index]);
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}
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return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
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}
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