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cmd: avb2.0: avb command for performing verification

Enable a "avb" command to execute Android Verified
Boot 2.0 operations. It includes such subcommands:
  avb init - initialize avb2 subsystem
  avb read_rb - read rollback index
  avb write_rb - write rollback index
  avb is_unlocked - check device lock state
  avb get_uuid - read and print uuid of a partition
  avb read_part - read data from partition
  avb read_part_hex - read data from partition and output to stdout
  avb write_part - write data to partition
  avb verify - run full verification chain

Signed-off-by: Igor Opaniuk <igor.opaniuk@linaro.org>
tags/2020-06-01
Igor Opaniuk 2 years ago
committed by Tom Rini
parent
commit
60b2f9e7b9
3 changed files with 376 additions and 0 deletions
  1. +16
    -0
      cmd/Kconfig
  2. +3
    -0
      cmd/Makefile
  3. +357
    -0
      cmd/avb.c

+ 16
- 0
cmd/Kconfig View File

@@ -1754,6 +1754,22 @@ config CMD_TRACE
for analsys (e.g. using bootchart). See doc/README.trace for full
details.

config CMD_AVB
bool "avb - Android Verified Boot 2.0 operations"
depends on LIBAVB
default n
help
Enables a "avb" command to perform verification of partitions using
Android Verified Boot 2.0 functionality. It includes such subcommands:
avb init - initialize avb2 subsystem
avb read_rb - read rollback index
avb write_rb - write rollback index
avb is_unlocked - check device lock state
avb get_uuid - read and print uuid of a partition
avb read_part - read data from partition
avb read_part_hex - read data from partition and output to stdout
avb write_part - write data to partition
avb verify - run full verification chain
endmenu

config CMD_UBI


+ 3
- 0
cmd/Makefile View File

@@ -155,6 +155,9 @@ obj-$(CONFIG_CMD_REGULATOR) += regulator.o

obj-$(CONFIG_CMD_BLOB) += blob.o

# Android Verified Boot 2.0
obj-$(CONFIG_CMD_AVB) += avb.o

obj-$(CONFIG_X86) += x86/
endif # !CONFIG_SPL_BUILD



+ 357
- 0
cmd/avb.c View File

@@ -0,0 +1,357 @@

/*
* (C) Copyright 2018, Linaro Limited
*
* SPDX-License-Identifier: GPL-2.0+
*/

#include <avb_verify.h>
#include <command.h>
#include <image.h>
#include <malloc.h>
#include <mmc.h>

#define AVB_BOOTARGS "avb_bootargs"
static struct AvbOps *avb_ops;

static const char * const requested_partitions[] = {"boot",
"system",
"vendor",
NULL};

int do_avb_init(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned long mmc_dev;

if (argc != 2)
return CMD_RET_USAGE;

mmc_dev = simple_strtoul(argv[1], NULL, 16);

if (avb_ops)
avb_ops_free(avb_ops);

avb_ops = avb_ops_alloc(mmc_dev);
if (avb_ops)
return CMD_RET_SUCCESS;

return CMD_RET_FAILURE;
}

int do_avb_read_part(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
const char *part;
s64 offset;
size_t bytes, bytes_read = 0;
void *buffer;

if (!avb_ops) {
printf("AVB 2.0 is not initialized, please run 'avb init'\n");
return CMD_RET_USAGE;
}

if (argc != 5)
return CMD_RET_USAGE;

part = argv[1];
offset = simple_strtoul(argv[2], NULL, 16);
bytes = simple_strtoul(argv[3], NULL, 16);
buffer = (void *)simple_strtoul(argv[4], NULL, 16);

if (avb_ops->read_from_partition(avb_ops, part, offset, bytes,
buffer, &bytes_read) ==
AVB_IO_RESULT_OK) {
printf("Read %zu bytes\n", bytes_read);
return CMD_RET_SUCCESS;
}

return CMD_RET_FAILURE;
}

int do_avb_read_part_hex(cmd_tbl_t *cmdtp, int flag, int argc,
char *const argv[])
{
const char *part;
s64 offset;
size_t bytes, bytes_read = 0;
char *buffer;

if (!avb_ops) {
printf("AVB 2.0 is not initialized, please run 'avb init'\n");
return CMD_RET_USAGE;
}

if (argc != 4)
return CMD_RET_USAGE;

part = argv[1];
offset = simple_strtoul(argv[2], NULL, 16);
bytes = simple_strtoul(argv[3], NULL, 16);

buffer = malloc(bytes);
if (!buffer) {
printf("Failed to tlb_allocate buffer for data\n");
return CMD_RET_FAILURE;
}
memset(buffer, 0, bytes);

if (avb_ops->read_from_partition(avb_ops, part, offset, bytes, buffer,
&bytes_read) == AVB_IO_RESULT_OK) {
printf("Requested %zu, read %zu bytes\n", bytes, bytes_read);
printf("Data: ");
for (int i = 0; i < bytes_read; i++)
printf("%02X", buffer[i]);

printf("\n");

free(buffer);
return CMD_RET_SUCCESS;
}

free(buffer);
return CMD_RET_FAILURE;
}

int do_avb_write_part(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
const char *part;
s64 offset;
size_t bytes;
void *buffer;

if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}

if (argc != 5)
return CMD_RET_USAGE;

part = argv[1];
offset = simple_strtoul(argv[2], NULL, 16);
bytes = simple_strtoul(argv[3], NULL, 16);
buffer = (void *)simple_strtoul(argv[4], NULL, 16);

if (avb_ops->write_to_partition(avb_ops, part, offset, bytes, buffer) ==
AVB_IO_RESULT_OK) {
printf("Wrote %zu bytes\n", bytes);
return CMD_RET_SUCCESS;
}

return CMD_RET_FAILURE;
}

int do_avb_read_rb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
size_t index;
u64 rb_idx;

if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}

if (argc != 2)
return CMD_RET_USAGE;

index = (size_t)simple_strtoul(argv[1], NULL, 16);

if (avb_ops->read_rollback_index(avb_ops, index, &rb_idx) ==
AVB_IO_RESULT_OK) {
printf("Rollback index: %llu\n", rb_idx);
return CMD_RET_SUCCESS;
}
return CMD_RET_FAILURE;
}

int do_avb_write_rb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
size_t index;
u64 rb_idx;

if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}

if (argc != 3)
return CMD_RET_USAGE;

index = (size_t)simple_strtoul(argv[1], NULL, 16);
rb_idx = simple_strtoul(argv[2], NULL, 16);

if (avb_ops->write_rollback_index(avb_ops, index, rb_idx) ==
AVB_IO_RESULT_OK)
return CMD_RET_SUCCESS;

return CMD_RET_FAILURE;
}

int do_avb_get_uuid(cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
const char *part;
char buffer[UUID_STR_LEN + 1];

if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}

if (argc != 2)
return CMD_RET_USAGE;

part = argv[1];

if (avb_ops->get_unique_guid_for_partition(avb_ops, part, buffer,
UUID_STR_LEN + 1) ==
AVB_IO_RESULT_OK) {
printf("'%s' UUID: %s\n", part, buffer);
return CMD_RET_SUCCESS;
}

return CMD_RET_FAILURE;
}

int do_avb_verify_part(cmd_tbl_t *cmdtp, int flag,
int argc, char *const argv[])
{
AvbSlotVerifyResult slot_result;
AvbSlotVerifyData *out_data;

bool unlocked = false;
int res = CMD_RET_FAILURE;

if (!avb_ops) {
printf("AVB 2.0 is not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}

if (argc != 1)
return CMD_RET_USAGE;

printf("## Android Verified Boot 2.0 version %s\n",
avb_version_string());

if (avb_ops->read_is_device_unlocked(avb_ops, &unlocked) !=
AVB_IO_RESULT_OK) {
printf("Can't determine device lock state.\n");
return CMD_RET_FAILURE;
}

slot_result =
avb_slot_verify(avb_ops,
requested_partitions,
"",
unlocked,
AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
&out_data);

switch (slot_result) {
case AVB_SLOT_VERIFY_RESULT_OK:
printf("Verification passed successfully\n");

/* export additional bootargs to AVB_BOOTARGS env var */
env_set(AVB_BOOTARGS, out_data->cmdline);

res = CMD_RET_SUCCESS;
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION:
printf("Verification failed\n");
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_IO:
printf("I/O error occurred during verification\n");
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_OOM:
printf("OOM error occurred during verification\n");
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA:
printf("Corrupted dm-verity metadata detected\n");
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION:
printf("Unsupported version avbtool was used\n");
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX:
printf("Checking rollback index failed\n");
break;
case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED:
printf("Public key was rejected\n");
break;
default:
printf("Unknown error occurred\n");
}

return res;
}

int do_avb_is_unlocked(cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
bool unlock;

if (!avb_ops) {
printf("AVB not initialized, run 'avb init' first\n");
return CMD_RET_FAILURE;
}

if (argc != 1) {
printf("--%s(-1)\n", __func__);
return CMD_RET_USAGE;
}

if (avb_ops->read_is_device_unlocked(avb_ops, &unlock) ==
AVB_IO_RESULT_OK) {
printf("Unlocked = %d\n", unlock);
return CMD_RET_SUCCESS;
}

return CMD_RET_FAILURE;
}

static cmd_tbl_t cmd_avb[] = {
U_BOOT_CMD_MKENT(init, 2, 0, do_avb_init, "", ""),
U_BOOT_CMD_MKENT(read_rb, 2, 0, do_avb_read_rb, "", ""),
U_BOOT_CMD_MKENT(write_rb, 3, 0, do_avb_write_rb, "", ""),
U_BOOT_CMD_MKENT(is_unlocked, 1, 0, do_avb_is_unlocked, "", ""),
U_BOOT_CMD_MKENT(get_uuid, 2, 0, do_avb_get_uuid, "", ""),
U_BOOT_CMD_MKENT(read_part, 5, 0, do_avb_read_part, "", ""),
U_BOOT_CMD_MKENT(read_part_hex, 4, 0, do_avb_read_part_hex, "", ""),
U_BOOT_CMD_MKENT(write_part, 5, 0, do_avb_write_part, "", ""),
U_BOOT_CMD_MKENT(verify, 1, 0, do_avb_verify_part, "", ""),
};

static int do_avb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
cmd_tbl_t *cp;

cp = find_cmd_tbl(argv[1], cmd_avb, ARRAY_SIZE(cmd_avb));

argc--;
argv++;

if (!cp || argc > cp->maxargs)
return CMD_RET_USAGE;

if (flag == CMD_FLAG_REPEAT)
return CMD_RET_FAILURE;

return cp->cmd(cmdtp, flag, argc, argv);
}

U_BOOT_CMD(
avb, 29, 0, do_avb,
"Provides commands for testing Android Verified Boot 2.0 functionality",
"init <dev> - initialize avb2 for <dev>\n"
"avb read_rb <num> - read rollback index at location <num>\n"
"avb write_rb <num> <rb> - write rollback index <rb> to <num>\n"
"avb is_unlocked - returns unlock status of the device\n"
"avb get_uuid <partname> - read and print uuid of partition <part>\n"
"avb read_part <partname> <offset> <num> <addr> - read <num> bytes from\n"
" partition <partname> to buffer <addr>\n"
"avb read_part_hex <partname> <offset> <num> - read <num> bytes from\n"
" partition <partname> and print to stdout\n"
"avb write_part <partname> <offset> <num> <addr> - write <num> bytes to\n"
" <partname> by <offset> using data from <addr>\n"
"avb verify - run verification process using hash data\n"
" from vbmeta structure\n"
);

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