[U-Boot] [PATCH 4/8] cmd: avb2.0: avb command for performing verification
Igor Opaniuk
igor.opaniuk at linaro.org
Wed Apr 25 13:18:01 UTC 2018
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 at linaro.org>
---
cmd/Kconfig | 15 +++
cmd/Makefile | 3 +
cmd/avb.c | 351 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 369 insertions(+)
create mode 100644 cmd/avb.c
diff --git a/cmd/Kconfig b/cmd/Kconfig
index bc1d2f3..96695ff 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1675,6 +1675,21 @@ 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_AB
+ 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
diff --git a/cmd/Makefile b/cmd/Makefile
index c4269ac..bbf6c2a 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -151,6 +151,9 @@ 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
diff --git a/cmd/avb.c b/cmd/avb.c
new file mode 100644
index 0000000..d040906
--- /dev/null
+++ b/cmd/avb.c
@@ -0,0 +1,351 @@
+
+/*
+ * (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, &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"
+ );
--
2.7.4
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