Remove support for AVB 1.0. (6cdd9bd7) · Commits · e / os / android_system_core

fs_mgr/Android.bp

+0 −1

Original line number	Diff line number	Diff line
		@@ -69,7 +69,6 @@ cc_defaults {
		"file_wait.cpp",
		"fs_mgr.cpp",
		"fs_mgr_format.cpp",
		"fs_mgr_verity.cpp",
		"fs_mgr_dm_linear.cpp",
		"fs_mgr_overlayfs.cpp",
		"fs_mgr_roots.cpp",

fs_mgr/fs_mgr.cpp

+24 −33

Original line number	Diff line number	Diff line
		@@ -1443,14 +1443,6 @@ MountAllResult fs_mgr_mount_all(Fstab* fstab, int mount_mode) {
		// Skips mounting the device.
		continue;
		}
		} else if ((current_entry.fs_mgr_flags.verify)) {
		int rc = fs_mgr_setup_verity(&current_entry, true);
		if (rc == FS_MGR_SETUP_VERITY_DISABLED \|\| rc == FS_MGR_SETUP_VERITY_SKIPPED) {
		LINFO << "Verity disabled";
		} else if (rc != FS_MGR_SETUP_VERITY_SUCCESS) {
		LERROR << "Could not set up verified partition, skipping!";
		continue;
		}
		}

		int last_idx_inspected;
		@@ -1615,13 +1607,6 @@ int fs_mgr_umount_all(android::fs_mgr::Fstab* fstab) {
		ret \|= FsMgrUmountStatus::ERROR_VERITY;
		continue;
		}
		} else if ((current_entry.fs_mgr_flags.verify)) {
		if (!fs_mgr_teardown_verity(&current_entry)) {
		LERROR << "Failed to tear down verified partition on mount point: "
		<< current_entry.mount_point;
		ret \|= FsMgrUmountStatus::ERROR_VERITY;
		continue;
		}
		}
		}
		return ret;
		@@ -1914,14 +1899,6 @@ static int fs_mgr_do_mount_helper(Fstab* fstab, const std::string& n_name,
		// Skips mounting the device.
		continue;
		}
		} else if (fstab_entry.fs_mgr_flags.verify) {
		int rc = fs_mgr_setup_verity(&fstab_entry, true);
		if (rc == FS_MGR_SETUP_VERITY_DISABLED \|\| rc == FS_MGR_SETUP_VERITY_SKIPPED) {
		LINFO << "Verity disabled";
		} else if (rc != FS_MGR_SETUP_VERITY_SUCCESS) {
		LERROR << "Could not set up verified partition, skipping!";
		continue;
		}
		}

		int retry_count = 2;
		@@ -2138,7 +2115,7 @@ bool fs_mgr_swapon_all(const Fstab& fstab) {
		}

		bool fs_mgr_is_verity_enabled(const FstabEntry& entry) {
		if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
		if (!entry.fs_mgr_flags.avb) {
		return false;
		}

		@@ -2149,17 +2126,12 @@ bool fs_mgr_is_verity_enabled(const FstabEntry& entry) {
		return false;
		}

		const char* status;
		std::vector<DeviceMapper::TargetInfo> table;
		if (!dm.GetTableStatus(mount_point, &table) \|\| table.empty() \|\| table[0].data.empty()) {
		if (!entry.fs_mgr_flags.verify_at_boot) {
		return false;
		}
		status = "V";
		} else {
		status = table[0].data.c_str();
		}

		auto status = table[0].data.c_str();
		if (status == 'C' \|\| status == 'V') {
		return true;
		}
		@@ -2168,7 +2140,7 @@ bool fs_mgr_is_verity_enabled(const FstabEntry& entry) {
		}

		std::optional<HashtreeInfo> fs_mgr_get_hashtree_info(const android::fs_mgr::FstabEntry& entry) {
		if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
		if (!entry.fs_mgr_flags.avb) {
		return {};
		}
		DeviceMapper& dm = DeviceMapper::Instance();
		@@ -2204,7 +2176,7 @@ std::optional<HashtreeInfo> fs_mgr_get_hashtree_info(const android::fs_mgr::Fsta
		}

		bool fs_mgr_verity_is_check_at_most_once(const android::fs_mgr::FstabEntry& entry) {
		if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
		if (!entry.fs_mgr_flags.avb) {
		return false;
		}

		@@ -2340,3 +2312,22 @@ bool fs_mgr_mount_overlayfs_fstab_entry(const FstabEntry& entry) {
		LINFO << report << ret;
		return true;
		}

		bool fs_mgr_load_verity_state(int* mode) {
		// unless otherwise specified, use EIO mode.
		*mode = VERITY_MODE_EIO;

		// The bootloader communicates verity mode via the kernel commandline
		std::string verity_mode;
		if (!fs_mgr_get_boot_config("veritymode", &verity_mode)) {
		return false;
		}

		if (verity_mode == "enforcing") {
		*mode = VERITY_MODE_DEFAULT;
		} else if (verity_mode == "logging") {
		*mode = VERITY_MODE_LOGGING;
		}

		return true;
		}

fs_mgr/fs_mgr_fstab.cpp

+0 −2

Original line number	Diff line number	Diff line
		@@ -167,12 +167,10 @@ bool ParseFsMgrFlags(const std::string& flags, FstabEntry* entry) {
		CheckFlag("recoveryonly", recovery_only);
		CheckFlag("noemulatedsd", no_emulated_sd);
		CheckFlag("notrim", no_trim);
		CheckFlag("verify", verify);
		CheckFlag("formattable", formattable);
		CheckFlag("slotselect", slot_select);
		CheckFlag("latemount", late_mount);
		CheckFlag("nofail", no_fail);
		CheckFlag("verifyatboot", verify_at_boot);
		CheckFlag("quota", quota);
		CheckFlag("avb", avb);
		CheckFlag("logical", logical);

fs_mgr/fs_mgr_verity.cpp

deleted100644 → 0

+0 −557

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2013 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#include <ctype.h>
		#include <errno.h>
		#include <fcntl.h>
		#include <inttypes.h>
		#include <libgen.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/mount.h>
		#include <sys/stat.h>
		#include <sys/types.h>
		#include <sys/wait.h>
		#include <time.h>
		#include <unistd.h>

		#include <android-base/file.h>
		#include <android-base/properties.h>
		#include <android-base/strings.h>
		#include <android-base/unique_fd.h>
		#include <crypto_utils/android_pubkey.h>
		#include <cutils/properties.h>
		#include <fs_mgr/file_wait.h>
		#include <libdm/dm.h>
		#include <logwrap/logwrap.h>
		#include <openssl/obj_mac.h>
		#include <openssl/rsa.h>
		#include <openssl/sha.h>

		#include "fec/io.h"

		#include "fs_mgr.h"
		#include "fs_mgr_dm_linear.h"
		#include "fs_mgr_priv.h"

		// Realistically, this file should be part of the android::fs_mgr namespace;
		using namespace android::fs_mgr;

		#define VERITY_TABLE_RSA_KEY "/verity_key"
		#define VERITY_TABLE_HASH_IDX 8
		#define VERITY_TABLE_SALT_IDX 9

		#define VERITY_TABLE_OPT_RESTART "restart_on_corruption"
		#define VERITY_TABLE_OPT_LOGGING "ignore_corruption"
		#define VERITY_TABLE_OPT_IGNZERO "ignore_zero_blocks"

		#define VERITY_TABLE_OPT_FEC_FORMAT \
		"use_fec_from_device %s fec_start %" PRIu64 " fec_blocks %" PRIu64 \
		" fec_roots %u " VERITY_TABLE_OPT_IGNZERO
		#define VERITY_TABLE_OPT_FEC_ARGS 9

		#define METADATA_MAGIC 0x01564c54
		#define METADATA_TAG_MAX_LENGTH 63
		#define METADATA_EOD "eod"

		#define VERITY_LASTSIG_TAG "verity_lastsig"

		#define VERITY_STATE_TAG "verity_state"
		#define VERITY_STATE_HEADER 0x83c0ae9d
		#define VERITY_STATE_VERSION 1

		#define VERITY_KMSG_RESTART "dm-verity device corrupted"
		#define VERITY_KMSG_BUFSIZE 1024

		#define READ_BUF_SIZE 4096

		#define __STRINGIFY(x) #x
		#define STRINGIFY(x) __STRINGIFY(x)

		struct verity_state {
		uint32_t header;
		uint32_t version;
		int32_t mode;
		};

		extern struct fs_info info;

		static RSA load_key(const char path)
		{
		uint8_t key_data[ANDROID_PUBKEY_ENCODED_SIZE];

		auto f = std::unique_ptr<FILE, decltype(&fclose)>{fopen(path, "re"), fclose};
		if (!f) {
		LERROR << "Can't open " << path;
		return nullptr;
		}

		if (!fread(key_data, sizeof(key_data), 1, f.get())) {
		LERROR << "Could not read key!";
		return nullptr;
		}

		RSA* key = nullptr;
		if (!android_pubkey_decode(key_data, sizeof(key_data), &key)) {
		LERROR << "Could not parse key!";
		return nullptr;
		}

		return key;
		}

		static int verify_table(const uint8_t *signature, size_t signature_size,
		const char *table, uint32_t table_length)
		{
		RSA *key;
		uint8_t hash_buf[SHA256_DIGEST_LENGTH];
		int retval = -1;

		// Hash the table
		SHA256((uint8_t*)table, table_length, hash_buf);

		// Now get the public key from the keyfile
		key = load_key(VERITY_TABLE_RSA_KEY);
		if (!key) {
		LERROR << "Couldn't load verity keys";
		goto out;
		}

		// verify the result
		if (!RSA_verify(NID_sha256, hash_buf, sizeof(hash_buf), signature,
		signature_size, key)) {
		LERROR << "Couldn't verify table";
		goto out;
		}

		retval = 0;

		out:
		RSA_free(key);
		return retval;
		}

		static int verify_verity_signature(const struct fec_verity_metadata& verity)
		{
		if (verify_table(verity.signature, sizeof(verity.signature),
		verity.table, verity.table_length) == 0 \|\|
		verify_table(verity.ecc_signature, sizeof(verity.ecc_signature),
		verity.table, verity.table_length) == 0) {
		return 0;
		}

		return -1;
		}

		static int invalidate_table(char *table, size_t table_length)
		{
		size_t n = 0;
		size_t idx = 0;
		size_t cleared = 0;

		while (n < table_length) {
		if (table[n++] == ' ') {
		++idx;
		}

		if (idx != VERITY_TABLE_HASH_IDX && idx != VERITY_TABLE_SALT_IDX) {
		continue;
		}

		while (n < table_length && table[n] != ' ') {
		table[n++] = '0';
		}

		if (++cleared == 2) {
		return 0;
		}
		}

		return -1;
		}

		struct verity_table_params {
		char *table;
		int mode;
		struct fec_ecc_metadata ecc;
		const char *ecc_dev;
		};

		typedef bool (format_verity_table_func)(char buf, const size_t bufsize,
		const struct verity_table_params *params);

		static bool format_verity_table(char *buf, const size_t bufsize,
		const struct verity_table_params *params)
		{
		const char *mode_flag = NULL;
		int res = -1;

		if (params->mode == VERITY_MODE_RESTART) {
		mode_flag = VERITY_TABLE_OPT_RESTART;
		} else if (params->mode == VERITY_MODE_LOGGING) {
		mode_flag = VERITY_TABLE_OPT_LOGGING;
		}

		if (params->ecc.valid) {
		if (mode_flag) {
		res = snprintf(buf, bufsize,
		"%s %u %s " VERITY_TABLE_OPT_FEC_FORMAT,
		params->table, 1 + VERITY_TABLE_OPT_FEC_ARGS, mode_flag, params->ecc_dev,
		params->ecc.start / FEC_BLOCKSIZE, params->ecc.blocks, params->ecc.roots);
		} else {
		res = snprintf(buf, bufsize,
		"%s %u " VERITY_TABLE_OPT_FEC_FORMAT,
		params->table, VERITY_TABLE_OPT_FEC_ARGS, params->ecc_dev,
		params->ecc.start / FEC_BLOCKSIZE, params->ecc.blocks, params->ecc.roots);
		}
		} else if (mode_flag) {
		res = snprintf(buf, bufsize, "%s 2 " VERITY_TABLE_OPT_IGNZERO " %s", params->table,
		mode_flag);
		} else {
		res = snprintf(buf, bufsize, "%s 1 " VERITY_TABLE_OPT_IGNZERO, params->table);
		}

		if (res < 0 \|\| (size_t)res >= bufsize) {
		LERROR << "Error building verity table; insufficient buffer size?";
		return false;
		}

		return true;
		}

		static bool format_legacy_verity_table(char *buf, const size_t bufsize,
		const struct verity_table_params *params)
		{
		int res;

		if (params->mode == VERITY_MODE_EIO) {
		res = strlcpy(buf, params->table, bufsize);
		} else {
		res = snprintf(buf, bufsize, "%s %d", params->table, params->mode);
		}

		if (res < 0 \|\| (size_t)res >= bufsize) {
		LERROR << "Error building verity table; insufficient buffer size?";
		return false;
		}

		return true;
		}

		static int load_verity_table(android::dm::DeviceMapper& dm, const std::string& name,
		uint64_t device_size, const struct verity_table_params* params,
		format_verity_table_func format) {
		android::dm::DmTable table;
		table.set_readonly(true);

		char buffer[DM_BUF_SIZE];
		if (!format(buffer, sizeof(buffer), params)) {
		LERROR << "Failed to format verity parameters";
		return -1;
		}

		android::dm::DmTargetVerityString target(0, device_size / 512, buffer);
		if (!table.AddTarget(std::make_unique<decltype(target)>(target))) {
		LERROR << "Failed to add verity target";
		return -1;
		}
		if (!dm.CreateDevice(name, table)) {
		LERROR << "Failed to create verity device \"" << name << "\"";
		return -1;
		}
		return 0;
		}

		static int read_partition(const char *path, uint64_t size)
		{
		char buf[READ_BUF_SIZE];
		ssize_t size_read;
		android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(path, O_RDONLY \| O_CLOEXEC)));

		if (fd == -1) {
		PERROR << "Failed to open " << path;
		return -errno;
		}

		while (size) {
		size_read = TEMP_FAILURE_RETRY(read(fd, buf, READ_BUF_SIZE));
		if (size_read == -1) {
		PERROR << "Error in reading partition " << path;
		return -errno;
		}
		size -= size_read;
		}

		return 0;
		}

		bool fs_mgr_load_verity_state(int* mode) {
		// unless otherwise specified, use EIO mode.
		*mode = VERITY_MODE_EIO;

		// The bootloader communicates verity mode via the kernel commandline
		std::string verity_mode;
		if (!fs_mgr_get_boot_config("veritymode", &verity_mode)) {
		return false;
		}

		if (verity_mode == "enforcing") {
		*mode = VERITY_MODE_DEFAULT;
		} else if (verity_mode == "logging") {
		*mode = VERITY_MODE_LOGGING;
		}

		return true;
		}

		// Update the verity table using the actual block device path.
		// Two cases:
		// Case-1: verity table is shared for devices with different by-name prefix.
		// Example:
		// verity table token: /dev/block/bootdevice/by-name/vendor
		// blk_device-1 (non-A/B): /dev/block/platform/soc.0/7824900.sdhci/by-name/vendor
		// blk_device-2 (A/B): /dev/block/platform/soc.0/f9824900.sdhci/by-name/vendor_a
		//
		// Case-2: append A/B suffix in the verity table.
		// Example:
		// verity table token: /dev/block/platform/soc.0/7824900.sdhci/by-name/vendor
		// blk_device: /dev/block/platform/soc.0/7824900.sdhci/by-name/vendor_a
		static void update_verity_table_blk_device(const std::string& blk_device, char** table,
		bool slot_select) {
		bool updated = false;
		std::string result, ab_suffix;
		auto tokens = android::base::Split(*table, " ");

		// If slot_select is set, it means blk_device is already updated with ab_suffix.
		if (slot_select) ab_suffix = fs_mgr_get_slot_suffix();

		for (const auto& token : tokens) {
		std::string new_token;
		if (android::base::StartsWith(token, "/dev/block/")) {
		if (token == blk_device) return; // no need to update if they're already the same.
		std::size_t found1 = blk_device.find("by-name");
		std::size_t found2 = token.find("by-name");
		if (found1 != std::string::npos && found2 != std::string::npos &&
		blk_device.substr(found1) == token.substr(found2) + ab_suffix) {
		new_token = blk_device;
		}
		}

		if (!new_token.empty()) {
		updated = true;
		LINFO << "Verity table: updated block device from '" << token << "' to '" << new_token
		<< "'";
		} else {
		new_token = token;
		}

		if (result.empty()) {
		result = new_token;
		} else {
		result += " " + new_token;
		}
		}

		if (!updated) {
		return;
		}

		free(*table);
		*table = strdup(result.c_str());
		}

		// prepares the verity enabled (MF_VERIFY / MF_VERIFYATBOOT) fstab record for
		// mount. The 'wait_for_verity_dev' parameter makes this function wait for the
		// verity device to get created before return
		int fs_mgr_setup_verity(FstabEntry* entry, bool wait_for_verity_dev) {
		int retval = FS_MGR_SETUP_VERITY_FAIL;
		int fd = -1;
		std::string verity_blk_name;
		struct fec_handle *f = NULL;
		struct fec_verity_metadata verity;
		struct verity_table_params params = { .table = NULL };

		const std::string mount_point(basename(entry->mount_point.c_str()));
		bool verified_at_boot = false;

		android::dm::DeviceMapper& dm = android::dm::DeviceMapper::Instance();

		if (fec_open(&f, entry->blk_device.c_str(), O_RDONLY, FEC_VERITY_DISABLE, FEC_DEFAULT_ROOTS) <
		0) {
		PERROR << "Failed to open '" << entry->blk_device << "'";
		return retval;
		}

		// read verity metadata
		if (fec_verity_get_metadata(f, &verity) < 0) {
		PERROR << "Failed to get verity metadata '" << entry->blk_device << "'";
		// Allow verity disabled when the device is unlocked without metadata
		if (fs_mgr_is_device_unlocked()) {
		retval = FS_MGR_SETUP_VERITY_SKIPPED;
		LWARNING << "Allow invalid metadata when the device is unlocked";
		}
		goto out;
		}

		#ifdef ALLOW_ADBD_DISABLE_VERITY
		if (verity.disabled) {
		retval = FS_MGR_SETUP_VERITY_DISABLED;
		LINFO << "Attempt to cleanly disable verity - only works in USERDEBUG/ENG";
		goto out;
		}
		#endif

		// read ecc metadata
		if (fec_ecc_get_metadata(f, &params.ecc) < 0) {
		params.ecc.valid = false;
		}

		params.ecc_dev = entry->blk_device.c_str();

		if (!fs_mgr_load_verity_state(&params.mode)) {
		/* if accessing or updating the state failed, switch to the default
		* safe mode. This makes sure the device won't end up in an endless
		* restart loop, and no corrupted data will be exposed to userspace
		* without a warning. */
		params.mode = VERITY_MODE_EIO;
		}

		if (!verity.table) {
		goto out;
		}

		params.table = strdup(verity.table);
		if (!params.table) {
		goto out;
		}

		// verify the signature on the table
		if (verify_verity_signature(verity) < 0) {
		// Allow signature verification error when the device is unlocked
		if (fs_mgr_is_device_unlocked()) {
		retval = FS_MGR_SETUP_VERITY_SKIPPED;
		LWARNING << "Allow signature verification error when the device is unlocked";
		goto out;
		}
		if (params.mode == VERITY_MODE_LOGGING) {
		// the user has been warned, allow mounting without dm-verity
		retval = FS_MGR_SETUP_VERITY_SKIPPED;
		goto out;
		}

		// invalidate root hash and salt to trigger device-specific recovery
		if (invalidate_table(params.table, verity.table_length) < 0) {
		goto out;
		}
		}

		LINFO << "Enabling dm-verity for " << mount_point.c_str()
		<< " (mode " << params.mode << ")";

		// Update the verity params using the actual block device path
		update_verity_table_blk_device(entry->blk_device, &params.table,
		entry->fs_mgr_flags.slot_select);

		// load the verity mapping table
		if (load_verity_table(dm, mount_point, verity.data_size, &params, format_verity_table) == 0) {
		goto loaded;
		}

		if (params.ecc.valid) {
		// kernel may not support error correction, try without
		LINFO << "Disabling error correction for " << mount_point.c_str();
		params.ecc.valid = false;

		if (load_verity_table(dm, mount_point, verity.data_size, &params, format_verity_table) == 0) {
		goto loaded;
		}
		}

		// try the legacy format for backwards compatibility
		if (load_verity_table(dm, mount_point, verity.data_size, &params, format_legacy_verity_table) ==
		0) {
		goto loaded;
		}

		if (params.mode != VERITY_MODE_EIO) {
		// as a last resort, EIO mode should always be supported
		LINFO << "Falling back to EIO mode for " << mount_point.c_str();
		params.mode = VERITY_MODE_EIO;

		if (load_verity_table(dm, mount_point, verity.data_size, &params,
		format_legacy_verity_table) == 0) {
		goto loaded;
		}
		}

		LERROR << "Failed to load verity table for " << mount_point.c_str();
		goto out;

		loaded:
		if (!dm.GetDmDevicePathByName(mount_point, &verity_blk_name)) {
		LERROR << "Couldn't get verity device number!";
		goto out;
		}

		// mark the underlying block device as read-only
		fs_mgr_set_blk_ro(entry->blk_device);

		// Verify the entire partition in one go
		// If there is an error, allow it to mount as a normal verity partition.
		if (entry->fs_mgr_flags.verify_at_boot) {
		LINFO << "Verifying partition " << entry->blk_device << " at boot";
		int err = read_partition(verity_blk_name.c_str(), verity.data_size);
		if (!err) {
		LINFO << "Verified verity partition " << entry->blk_device << " at boot";
		verified_at_boot = true;
		}
		}

		// assign the new verity block device as the block device
		if (!verified_at_boot) {
		entry->blk_device = verity_blk_name;
		} else if (!dm.DeleteDevice(mount_point)) {
		LERROR << "Failed to remove verity device " << mount_point.c_str();
		goto out;
		}

		// make sure we've set everything up properly
		if (wait_for_verity_dev && !WaitForFile(entry->blk_device, 1s)) {
		goto out;
		}

		retval = FS_MGR_SETUP_VERITY_SUCCESS;

		out:
		if (fd != -1) {
		close(fd);
		}

		fec_close(f);
		free(params.table);

		return retval;
		}

		bool fs_mgr_teardown_verity(FstabEntry* entry) {
		const std::string mount_point(basename(entry->mount_point.c_str()));
		if (!android::fs_mgr::UnmapDevice(mount_point)) {
		return false;
		}
		LINFO << "Unmapped verity device " << mount_point;
		return true;
		}

fs_mgr/include_fstab/fstab/fstab.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -63,7 +63,6 @@ struct FstabEntry {
		bool nonremovable : 1;
		bool vold_managed : 1;
		bool recovery_only : 1;
		bool verify : 1;
		bool no_emulated_sd : 1; // No emulated sdcard daemon; sd card is the only external
		// storage.
		bool no_trim : 1;
		@@ -72,7 +71,6 @@ struct FstabEntry {
		bool slot_select : 1;
		bool late_mount : 1;
		bool no_fail : 1;
		bool verify_at_boot : 1;
		bool quota : 1;
		bool avb : 1;
		bool logical : 1;