/*
* Copyright (C) 2015 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 "FsCrypt.h"
#include "KeyStorage.h"
#include "KeyUtil.h"
#include "Utils.h"
#include "VoldUtil.h"
#include <algorithm>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <selinux/android.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <private/android_filesystem_config.h>
#include "android/os/IVold.h"
#include "cryptfs.h"
#define EMULATED_USES_SELINUX 0
#define MANAGE_MISC_DIRS 0
#include <cutils/fs.h>
#include <cutils/properties.h>
#include <fscrypt/fscrypt.h>
#include <keyutils.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
using android::base::StringPrintf;
using android::fs_mgr::GetEntryForMountPoint;
using android::vold::kEmptyAuthentication;
using android::vold::KeyBuffer;
using android::vold::writeStringToFile;
namespace {
struct PolicyKeyRef {
std::string contents_mode;
std::string filenames_mode;
std::string key_raw_ref;
};
const std::string device_key_dir = std::string() + DATA_MNT_POINT + fscrypt_unencrypted_folder;
const std::string device_key_path = device_key_dir + "/key";
const std::string device_key_temp = device_key_dir + "/temp";
const std::string user_key_dir = std::string() + DATA_MNT_POINT + "/misc/vold/user_keys";
const std::string user_key_temp = user_key_dir + "/temp";
const std::string prepare_subdirs_path = "/system/bin/vold_prepare_subdirs";
const std::string systemwide_volume_key_dir =
std::string() + DATA_MNT_POINT + "/misc/vold/volume_keys";
bool s_global_de_initialized = false;
// Some users are ephemeral, don't try to wipe their keys from disk
std::set<userid_t> s_ephemeral_users;
// Map user ids to key references
std::map<userid_t, std::string> s_de_key_raw_refs;
std::map<userid_t, std::string> s_ce_key_raw_refs;
// TODO abolish this map, per b/26948053
std::map<userid_t, KeyBuffer> s_ce_keys;
} // namespace
static bool fscrypt_is_emulated() {
return property_get_bool("persist.sys.emulate_fbe", false);
}
static const char* escape_empty(const std::string& value) {
return value.empty() ? "null" : value.c_str();
}
static std::string get_de_key_path(userid_t user_id) {
return StringPrintf("%s/de/%d", user_key_dir.c_str(), user_id);
}
static std::string get_ce_key_directory_path(userid_t user_id) {
return StringPrintf("%s/ce/%d", user_key_dir.c_str(), user_id);
}
// Returns the keys newest first
static std::vector<std::string> get_ce_key_paths(const std::string& directory_path) {
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(directory_path.c_str()), closedir);
if (!dirp) {
PLOG(ERROR) << "Unable to open ce key directory: " + directory_path;
return std::vector<std::string>();
}
std::vector<std::string> result;
for (;;) {
errno = 0;
auto const entry = readdir(dirp.get());
if (!entry) {
if (errno) {
PLOG(ERROR) << "Unable to read ce key directory: " + directory_path;
return std::vector<std::string>();
}
break;
}
if (entry->d_type != DT_DIR || entry->d_name[0] != 'c') {
LOG(DEBUG) << "Skipping non-key " << entry->d_name;
continue;
}
result.emplace_back(directory_path + "/" + entry->d_name);
}
std::sort(result.begin(), result.end());
std::reverse(result.begin(), result.end());
return result;
}
static std::string get_ce_key_current_path(const std::string& directory_path) {
return directory_path + "/current";
}
static bool get_ce_key_new_path(const std::string& directory_path,
const std::vector<std::string>& paths, std::string* ce_key_path) {
if (paths.empty()) {
*ce_key_path = get_ce_key_current_path(directory_path);
return true;
}
for (unsigned int i = 0; i < UINT_MAX; i++) {
auto const candidate = StringPrintf("%s/cx%010u", directory_path.c_str(), i);
if (paths[0] < candidate) {
*ce_key_path = candidate;
return true;
}
}
return false;
}
// Discard all keys but the named one; rename it to canonical name.
// No point in acting on errors in this; ignore them.
static void fixate_user_ce_key(const std::string& directory_path, const std::string& to_fix,
const std::vector<std::string>& paths) {
for (auto const other_path : paths) {
if (other_path != to_fix) {
android::vold::destroyKey(other_path);
}
}
auto const current_path = get_ce_key_current_path(directory_path);
if (to_fix != current_path) {
LOG(DEBUG) << "Renaming " << to_fix << " to " << current_path;
if (rename(to_fix.c_str(), current_path.c_str()) != 0) {
PLOG(WARNING) << "Unable to rename " << to_fix << " to " << current_path;
return;
}
}
android::vold::FsyncDirectory(directory_path);
}
static bool read_and_fixate_user_ce_key(userid_t user_id,
const android::vold::KeyAuthentication& auth,
KeyBuffer* ce_key) {
auto const directory_path = get_ce_key_directory_path(user_id);
auto const paths = get_ce_key_paths(directory_path);
for (auto const ce_key_path : paths) {
LOG(DEBUG) << "Trying user CE key " << ce_key_path;
if (android::vold::retrieveKey(ce_key_path, auth, ce_key)) {
LOG(DEBUG) << "Successfully retrieved key";
fixate_user_ce_key(directory_path, ce_key_path, paths);
return true;
}
}
LOG(ERROR) << "Failed to find working ce key for user " << user_id;
return false;
}
static bool read_and_install_user_ce_key(userid_t user_id,
const android::vold::KeyAuthentication& auth) {
if (s_ce_key_raw_refs.count(user_id) != 0) return true;
KeyBuffer ce_key;
if (!read_and_fixate_user_ce_key(user_id, auth, &ce_key)) return false;
std::string ce_raw_ref;
if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
s_ce_keys[user_id] = std::move(ce_key);
s_ce_key_raw_refs[user_id] = ce_raw_ref;
LOG(DEBUG) << "Installed ce key for user " << user_id;
return true;
}
static bool prepare_dir(const std::string& dir, mode_t mode, uid_t uid, gid_t gid) {
LOG(DEBUG) << "Preparing: " << dir;
if (fs_prepare_dir(dir.c_str(), mode, uid, gid) != 0) {
PLOG(ERROR) << "Failed to prepare " << dir;
return false;
}
return true;
}
static bool destroy_dir(const std::string& dir) {
LOG(DEBUG) << "Destroying: " << dir;
if (rmdir(dir.c_str()) != 0 && errno != ENOENT) {
PLOG(ERROR) << "Failed to destroy " << dir;
return false;
}
return true;
}
// NB this assumes that there is only one thread listening for crypt commands, because
// it creates keys in a fixed location.
static bool create_and_install_user_keys(userid_t user_id, bool create_ephemeral) {
KeyBuffer de_key, ce_key;
if (!android::vold::randomKey(&de_key)) return false;
if (!android::vold::randomKey(&ce_key)) return false;
if (create_ephemeral) {
// If the key should be created as ephemeral, don't store it.
s_ephemeral_users.insert(user_id);
} else {
auto const directory_path = get_ce_key_directory_path(user_id);
if (!prepare_dir(directory_path, 0700, AID_ROOT, AID_ROOT)) return false;
auto const paths = get_ce_key_paths(directory_path);
std::string ce_key_path;
if (!get_ce_key_new_path(directory_path, paths, &ce_key_path)) return false;
if (!android::vold::storeKeyAtomically(ce_key_path, user_key_temp, kEmptyAuthentication,
ce_key))
return false;
fixate_user_ce_key(directory_path, ce_key_path, paths);
// Write DE key second; once this is written, all is good.
if (!android::vold::storeKeyAtomically(get_de_key_path(user_id), user_key_temp,
kEmptyAuthentication, de_key))
return false;
}
std::string de_raw_ref;
if (!android::vold::installKey(de_key, &de_raw_ref)) return false;
s_de_key_raw_refs[user_id] = de_raw_ref;
std::string ce_raw_ref;
if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
s_ce_keys[user_id] = ce_key;
s_ce_key_raw_refs[user_id] = ce_raw_ref;
LOG(DEBUG) << "Created keys for user " << user_id;
return true;
}
static bool lookup_key_ref(const std::map<userid_t, std::string>& key_map, userid_t user_id,
std::string* raw_ref) {
auto refi = key_map.find(user_id);
if (refi == key_map.end()) {
LOG(DEBUG) << "Cannot find key for " << user_id;
return false;
}
*raw_ref = refi->second;
return true;
}
static void get_data_file_encryption_modes(PolicyKeyRef* key_ref) {
auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
if (entry == nullptr) {
return;
}
key_ref->contents_mode = entry->file_contents_mode;
key_ref->filenames_mode = entry->file_names_mode;
}
static bool ensure_policy(const PolicyKeyRef& key_ref, const std::string& path) {
return fscrypt_policy_ensure(path.c_str(), key_ref.key_raw_ref.data(),
key_ref.key_raw_ref.size(), key_ref.contents_mode.c_str(),
key_ref.filenames_mode.c_str()) == 0;
}
static bool is_numeric(const char* name) {
for (const char* p = name; *p != '\0'; p++) {
if (!isdigit(*p)) return false;
}
return true;
}
static bool load_all_de_keys() {
auto de_dir = user_key_dir + "/de";
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(de_dir.c_str()), closedir);
if (!dirp) {
PLOG(ERROR) << "Unable to read de key directory";
return false;
}
for (;;) {
errno = 0;
auto entry = readdir(dirp.get());
if (!entry) {
if (errno) {
PLOG(ERROR) << "Unable to read de key directory";
return false;
}
break;
}
if (entry->d_type != DT_DIR || !is_numeric(entry->d_name)) {
LOG(DEBUG) << "Skipping non-de-key " << entry->d_name;
continue;
}
userid_t user_id = std::stoi(entry->d_name);
if (s_de_key_raw_refs.count(user_id) == 0) {
auto key_path = de_dir + "/" + entry->d_name;
KeyBuffer key;
if (!android::vold::retrieveKey(key_path, kEmptyAuthentication, &key)) return false;
std::string raw_ref;
if (!android::vold::installKey(key, &raw_ref)) return false;
s_de_key_raw_refs[user_id] = raw_ref;
LOG(DEBUG) << "Installed de key for user " << user_id;
}
}
// fscrypt:TODO: go through all DE directories, ensure that all user dirs have the
// correct policy set on them, and that no rogue ones exist.
return true;
}
bool fscrypt_initialize_global_de() {
LOG(INFO) << "fscrypt_initialize_global_de";
if (s_global_de_initialized) {
LOG(INFO) << "Already initialized";
return true;
}
PolicyKeyRef device_ref;
if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication, device_key_path,
device_key_temp, &device_ref.key_raw_ref))
return false;
get_data_file_encryption_modes(&device_ref);
std::string modestring = device_ref.contents_mode + ":" + device_ref.filenames_mode;
std::string mode_filename = std::string("/data") + fscrypt_key_mode;
if (!android::vold::writeStringToFile(modestring, mode_filename)) return false;
std::string ref_filename = std::string("/data") + fscrypt_key_ref;
if (!android::vold::writeStringToFile(device_ref.key_raw_ref, ref_filename)) return false;
LOG(INFO) << "Wrote system DE key reference to:" << ref_filename;
if (!android::vold::FsyncDirectory(device_key_dir)) return false;
s_global_de_initialized = true;
return true;
}
bool fscrypt_init_user0() {
LOG(DEBUG) << "fscrypt_init_user0";
if (fscrypt_is_native()) {
if (!prepare_dir(user_key_dir, 0700, AID_ROOT, AID_ROOT)) return false;
if (!prepare_dir(user_key_dir + "/ce", 0700, AID_ROOT, AID_ROOT)) return false;
if (!prepare_dir(user_key_dir + "/de", 0700, AID_ROOT, AID_ROOT)) return false;
if (!android::vold::pathExists(get_de_key_path(0))) {
if (!create_and_install_user_keys(0, false)) return false;
}
// TODO: switch to loading only DE_0 here once framework makes
// explicit calls to install DE keys for secondary users
if (!load_all_de_keys()) return false;
}
// We can only safely prepare DE storage here, since CE keys are probably
// entangled with user credentials. The framework will always prepare CE
// storage once CE keys are installed.
if (!fscrypt_prepare_user_storage("", 0, 0, android::os::IVold::STORAGE_FLAG_DE)) {
LOG(ERROR) << "Failed to prepare user 0 storage";
return false;
}
// If this is a non-FBE device that recently left an emulated mode,
// restore user data directories to known-good state.
if (!fscrypt_is_native() && !fscrypt_is_emulated()) {
fscrypt_unlock_user_key(0, 0, "!", "!");
}
return true;
}
bool fscrypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral) {
LOG(DEBUG) << "fscrypt_vold_create_user_key for " << user_id << " serial " << serial;
if (!fscrypt_is_native()) {
return true;
}
// FIXME test for existence of key that is not loaded yet
if (s_ce_key_raw_refs.count(user_id) != 0) {
LOG(ERROR) << "Already exists, can't fscrypt_vold_create_user_key for " << user_id
<< " serial " << serial;
// FIXME should we fail the command?
return true;
}
if (!create_and_install_user_keys(user_id, ephemeral)) {
return false;
}
return true;
}
static void drop_caches() {
// Clean any dirty pages (otherwise they won't be dropped).
sync();
// Drop inode and page caches.
if (!writeStringToFile("3", "/proc/sys/vm/drop_caches")) {
PLOG(ERROR) << "Failed to drop caches during key eviction";
}
}
static bool evict_ce_key(userid_t user_id) {
s_ce_keys.erase(user_id);
bool success = true;
std::string raw_ref;
// If we haven't loaded the CE key, no need to evict it.
if (lookup_key_ref(s_ce_key_raw_refs, user_id, &raw_ref)) {
success &= android::vold::evictKey(raw_ref);
drop_caches();
}
s_ce_key_raw_refs.erase(user_id);
return success;
}
bool fscrypt_destroy_user_key(userid_t user_id) {
LOG(DEBUG) << "fscrypt_destroy_user_key(" << user_id << ")";
if (!fscrypt_is_native()) {
return true;
}
bool success = true;
std::string raw_ref;
success &= evict_ce_key(user_id);
success &=
lookup_key_ref(s_de_key_raw_refs, user_id, &raw_ref) && android::vold::evictKey(raw_ref);
s_de_key_raw_refs.erase(user_id);
auto it = s_ephemeral_users.find(user_id);
if (it != s_ephemeral_users.end()) {
s_ephemeral_users.erase(it);
} else {
for (auto const path : get_ce_key_paths(get_ce_key_directory_path(user_id))) {
success &= android::vold::destroyKey(path);
}
auto de_key_path = get_de_key_path(user_id);
if (android::vold::pathExists(de_key_path)) {
success &= android::vold::destroyKey(de_key_path);
} else {
LOG(INFO) << "Not present so not erasing: " << de_key_path;
}
}
return success;
}
static bool emulated_lock(const std::string& path) {
if (chmod(path.c_str(), 0000) != 0) {
PLOG(ERROR) << "Failed to chmod " << path;
return false;
}
#if EMULATED_USES_SELINUX
if (setfilecon(path.c_str(), "u:object_r:storage_stub_file:s0") != 0) {
PLOG(WARNING) << "Failed to setfilecon " << path;
return false;
}
#endif
return true;
}
static bool emulated_unlock(const std::string& path, mode_t mode) {
if (chmod(path.c_str(), mode) != 0) {
PLOG(ERROR) << "Failed to chmod " << path;
// FIXME temporary workaround for b/26713622
if (fscrypt_is_emulated()) return false;
}
#if EMULATED_USES_SELINUX
if (selinux_android_restorecon(path.c_str(), SELINUX_ANDROID_RESTORECON_FORCE) != 0) {
PLOG(WARNING) << "Failed to restorecon " << path;
// FIXME temporary workaround for b/26713622
if (fscrypt_is_emulated()) return false;
}
#endif
return true;
}
static bool parse_hex(const std::string& hex, std::string* result) {
if (hex == "!") {
*result = "";
return true;
}
if (android::vold::HexToStr(hex, *result) != 0) {
LOG(ERROR) << "Invalid FBE hex string"; // Don't log the string for security reasons
return false;
}
return true;
}
static std::string volkey_path(const std::string& misc_path, const std::string& volume_uuid) {
return misc_path + "/vold/volume_keys/" + volume_uuid + "/default";
}
static std::string volume_secdiscardable_path(const std::string& volume_uuid) {
return systemwide_volume_key_dir + "/" + volume_uuid + "/secdiscardable";
}
static bool read_or_create_volkey(const std::string& misc_path, const std::string& volume_uuid,
PolicyKeyRef* key_ref) {
auto secdiscardable_path = volume_secdiscardable_path(volume_uuid);
std::string secdiscardable_hash;
if (android::vold::pathExists(secdiscardable_path)) {
if (!android::vold::readSecdiscardable(secdiscardable_path, &secdiscardable_hash))
return false;
} else {
if (fs_mkdirs(secdiscardable_path.c_str(), 0700) != 0) {
PLOG(ERROR) << "Creating directories for: " << secdiscardable_path;
return false;
}
if (!android::vold::createSecdiscardable(secdiscardable_path, &secdiscardable_hash))
return false;
}
auto key_path = volkey_path(misc_path, volume_uuid);
if (fs_mkdirs(key_path.c_str(), 0700) != 0) {
PLOG(ERROR) << "Creating directories for: " << key_path;
return false;
}
android::vold::KeyAuthentication auth("", secdiscardable_hash);
if (!android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp",
&key_ref->key_raw_ref))
return false;
key_ref->contents_mode =
android::base::GetProperty("ro.crypto.volume.contents_mode", "aes-256-xts");
key_ref->filenames_mode =
android::base::GetProperty("ro.crypto.volume.filenames_mode", "aes-256-heh");
return true;
}
static bool destroy_volkey(const std::string& misc_path, const std::string& volume_uuid) {
auto path = volkey_path(misc_path, volume_uuid);
if (!android::vold::pathExists(path)) return true;
return android::vold::destroyKey(path);
}
bool fscrypt_add_user_key_auth(userid_t user_id, int serial, const std::string& token_hex,
const std::string& secret_hex) {
LOG(DEBUG) << "fscrypt_add_user_key_auth " << user_id << " serial=" << serial
<< " token_present=" << (token_hex != "!");
if (!fscrypt_is_native()) return true;
if (s_ephemeral_users.count(user_id) != 0) return true;
std::string token, secret;
if (!parse_hex(token_hex, &token)) return false;
if (!parse_hex(secret_hex, &secret)) return false;
auto auth =
secret.empty() ? kEmptyAuthentication : android::vold::KeyAuthentication(token, secret);
auto it = s_ce_keys.find(user_id);
if (it == s_ce_keys.end()) {
LOG(ERROR) << "Key not loaded into memory, can't change for user " << user_id;
return false;
}
const auto& ce_key = it->second;
auto const directory_path = get_ce_key_directory_path(user_id);
auto const paths = get_ce_key_paths(directory_path);
std::string ce_key_path;
if (!get_ce_key_new_path(directory_path, paths, &ce_key_path)) return false;
if (!android::vold::storeKeyAtomically(ce_key_path, user_key_temp, auth, ce_key)) return false;
if (!android::vold::FsyncDirectory(directory_path)) return false;
return true;
}
bool fscrypt_fixate_newest_user_key_auth(userid_t user_id) {
LOG(DEBUG) << "fscrypt_fixate_newest_user_key_auth " << user_id;
if (!fscrypt_is_native()) return true;
if (s_ephemeral_users.count(user_id) != 0) return true;
auto const directory_path = get_ce_key_directory_path(user_id);
auto const paths = get_ce_key_paths(directory_path);
if (paths.empty()) {
LOG(ERROR) << "No ce keys present, cannot fixate for user " << user_id;
return false;
}
fixate_user_ce_key(directory_path, paths[0], paths);
return true;
}
// TODO: rename to 'install' for consistency, and take flags to know which keys to install
bool fscrypt_unlock_user_key(userid_t user_id, int serial, const std::string& token_hex,
const std::string& secret_hex) {
LOG(DEBUG) << "fscrypt_unlock_user_key " << user_id << " serial=" << serial
<< " token_present=" << (token_hex != "!");
if (fscrypt_is_native()) {
if (s_ce_key_raw_refs.count(user_id) != 0) {
LOG(WARNING) << "Tried to unlock already-unlocked key for user " << user_id;
return true;
}
std::string token, secret;
if (!parse_hex(token_hex, &token)) return false;
if (!parse_hex(secret_hex, &secret)) return false;
android::vold::KeyAuthentication auth(token, secret);
if (!read_and_install_user_ce_key(user_id, auth)) {
LOG(ERROR) << "Couldn't read key for " << user_id;
return false;
}
} else {
// When in emulation mode, we just use chmod. However, we also
// unlock directories when not in emulation mode, to bring devices
// back into a known-good state.
if (!emulated_unlock(android::vold::BuildDataSystemCePath(user_id), 0771) ||
!emulated_unlock(android::vold::BuildDataMiscCePath(user_id), 01771) ||
!emulated_unlock(android::vold::BuildDataMediaCePath("", user_id), 0770) ||
!emulated_unlock(android::vold::BuildDataUserCePath("", user_id), 0771)) {
LOG(ERROR) << "Failed to unlock user " << user_id;
return false;
}
}
return true;
}
// TODO: rename to 'evict' for consistency
bool fscrypt_lock_user_key(userid_t user_id) {
LOG(DEBUG) << "fscrypt_lock_user_key " << user_id;
if (fscrypt_is_native()) {
return evict_ce_key(user_id);
} else if (fscrypt_is_emulated()) {
// When in emulation mode, we just use chmod
if (!emulated_lock(android::vold::BuildDataSystemCePath(user_id)) ||
!emulated_lock(android::vold::BuildDataMiscCePath(user_id)) ||
!emulated_lock(android::vold::BuildDataMediaCePath("", user_id)) ||
!emulated_lock(android::vold::BuildDataUserCePath("", user_id))) {
LOG(ERROR) << "Failed to lock user " << user_id;
return false;
}
}
return true;
}
static bool prepare_subdirs(const std::string& action, const std::string& volume_uuid,
userid_t user_id, int flags) {
if (0 != android::vold::ForkExecvp(
std::vector<std::string>{prepare_subdirs_path, action, volume_uuid,
std::to_string(user_id), std::to_string(flags)})) {
LOG(ERROR) << "vold_prepare_subdirs failed";
return false;
}
return true;
}
bool fscrypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_id, int serial,
int flags) {
LOG(DEBUG) << "fscrypt_prepare_user_storage for volume " << escape_empty(volume_uuid)
<< ", user " << user_id << ", serial " << serial << ", flags " << flags;
if (flags & android::os::IVold::STORAGE_FLAG_DE) {
// DE_sys key
auto system_legacy_path = android::vold::BuildDataSystemLegacyPath(user_id);
auto misc_legacy_path = android::vold::BuildDataMiscLegacyPath(user_id);
auto profiles_de_path = android::vold::BuildDataProfilesDePath(user_id);
// DE_n key
auto system_de_path = android::vold::BuildDataSystemDePath(user_id);
auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
if (volume_uuid.empty()) {
if (!prepare_dir(system_legacy_path, 0700, AID_SYSTEM, AID_SYSTEM)) return false;
#if MANAGE_MISC_DIRS
if (!prepare_dir(misc_legacy_path, 0750, multiuser_get_uid(user_id, AID_SYSTEM),
multiuser_get_uid(user_id, AID_EVERYBODY)))
return false;
#endif
if (!prepare_dir(profiles_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
if (!prepare_dir(system_de_path, 0770, AID_SYSTEM, AID_SYSTEM)) return false;
if (!prepare_dir(misc_de_path, 01771, AID_SYSTEM, AID_MISC)) return false;
if (!prepare_dir(vendor_de_path, 0771, AID_ROOT, AID_ROOT)) return false;
}
if (!prepare_dir(user_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
if (fscrypt_is_native()) {
PolicyKeyRef de_ref;
if (volume_uuid.empty()) {
if (!lookup_key_ref(s_de_key_raw_refs, user_id, &de_ref.key_raw_ref)) return false;
get_data_file_encryption_modes(&de_ref);
if (!ensure_policy(de_ref, system_de_path)) return false;
if (!ensure_policy(de_ref, misc_de_path)) return false;
if (!ensure_policy(de_ref, vendor_de_path)) return false;
} else {
if (!read_or_create_volkey(misc_de_path, volume_uuid, &de_ref)) return false;
}
if (!ensure_policy(de_ref, user_de_path)) return false;
}
}
if (flags & android::os::IVold::STORAGE_FLAG_CE) {
// CE_n key
auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id);
auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
auto media_ce_path = android::vold::BuildDataMediaCePath(volume_uuid, user_id);
auto user_ce_path = android::vold::BuildDataUserCePath(volume_uuid, user_id);
if (volume_uuid.empty()) {
if (!prepare_dir(system_ce_path, 0770, AID_SYSTEM, AID_SYSTEM)) return false;
if (!prepare_dir(misc_ce_path, 01771, AID_SYSTEM, AID_MISC)) return false;
if (!prepare_dir(vendor_ce_path, 0771, AID_ROOT, AID_ROOT)) return false;
}
if (!prepare_dir(media_ce_path, 0770, AID_MEDIA_RW, AID_MEDIA_RW)) return false;
if (!prepare_dir(user_ce_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
if (fscrypt_is_native()) {
PolicyKeyRef ce_ref;
if (volume_uuid.empty()) {
if (!lookup_key_ref(s_ce_key_raw_refs, user_id, &ce_ref.key_raw_ref)) return false;
get_data_file_encryption_modes(&ce_ref);
if (!ensure_policy(ce_ref, system_ce_path)) return false;
if (!ensure_policy(ce_ref, misc_ce_path)) return false;
if (!ensure_policy(ce_ref, vendor_ce_path)) return false;
} else {
if (!read_or_create_volkey(misc_ce_path, volume_uuid, &ce_ref)) return false;
}
if (!ensure_policy(ce_ref, media_ce_path)) return false;
if (!ensure_policy(ce_ref, user_ce_path)) return false;
}
if (volume_uuid.empty()) {
// Now that credentials have been installed, we can run restorecon
// over these paths
// NOTE: these paths need to be kept in sync with libselinux
android::vold::RestoreconRecursive(system_ce_path);
android::vold::RestoreconRecursive(vendor_ce_path);
android::vold::RestoreconRecursive(misc_ce_path);
}
}
if (!prepare_subdirs("prepare", volume_uuid, user_id, flags)) return false;
return true;
}
bool fscrypt_destroy_user_storage(const std::string& volume_uuid, userid_t user_id, int flags) {
LOG(DEBUG) << "fscrypt_destroy_user_storage for volume " << escape_empty(volume_uuid)
<< ", user " << user_id << ", flags " << flags;
bool res = true;
res &= prepare_subdirs("destroy", volume_uuid, user_id, flags);
if (flags & android::os::IVold::STORAGE_FLAG_CE) {
// CE_n key
auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id);
auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
auto media_ce_path = android::vold::BuildDataMediaCePath(volume_uuid, user_id);
auto user_ce_path = android::vold::BuildDataUserCePath(volume_uuid, user_id);
res &= destroy_dir(media_ce_path);
res &= destroy_dir(user_ce_path);
if (volume_uuid.empty()) {
res &= destroy_dir(system_ce_path);
res &= destroy_dir(misc_ce_path);
res &= destroy_dir(vendor_ce_path);
} else {
if (fscrypt_is_native()) {
res &= destroy_volkey(misc_ce_path, volume_uuid);
}
}
}
if (flags & android::os::IVold::STORAGE_FLAG_DE) {
// DE_sys key
auto system_legacy_path = android::vold::BuildDataSystemLegacyPath(user_id);
auto misc_legacy_path = android::vold::BuildDataMiscLegacyPath(user_id);
auto profiles_de_path = android::vold::BuildDataProfilesDePath(user_id);
// DE_n key
auto system_de_path = android::vold::BuildDataSystemDePath(user_id);
auto misc_de_path = android::vold::BuildDataMiscDePath(user_id);
auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
res &= destroy_dir(user_de_path);
if (volume_uuid.empty()) {
res &= destroy_dir(system_legacy_path);
#if MANAGE_MISC_DIRS
res &= destroy_dir(misc_legacy_path);
#endif
res &= destroy_dir(profiles_de_path);
res &= destroy_dir(system_de_path);
res &= destroy_dir(misc_de_path);
res &= destroy_dir(vendor_de_path);
} else {
if (fscrypt_is_native()) {
res &= destroy_volkey(misc_de_path, volume_uuid);
}
}
}
return res;
}
static bool destroy_volume_keys(const std::string& directory_path, const std::string& volume_uuid) {
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(directory_path.c_str()), closedir);
if (!dirp) {
PLOG(ERROR) << "Unable to open directory: " + directory_path;
return false;
}
bool res = true;
for (;;) {
errno = 0;
auto const entry = readdir(dirp.get());
if (!entry) {
if (errno) {
PLOG(ERROR) << "Unable to read directory: " + directory_path;
return false;
}
break;
}
if (entry->d_type != DT_DIR || entry->d_name[0] == '.') {
LOG(DEBUG) << "Skipping non-user " << entry->d_name;
continue;
}
res &= destroy_volkey(directory_path + "/" + entry->d_name, volume_uuid);
}
return res;
}
bool fscrypt_destroy_volume_keys(const std::string& volume_uuid) {
bool res = true;
LOG(DEBUG) << "fscrypt_destroy_volume_keys for volume " << escape_empty(volume_uuid);
auto secdiscardable_path = volume_secdiscardable_path(volume_uuid);
res &= android::vold::runSecdiscardSingle(secdiscardable_path);
res &= destroy_volume_keys("/data/misc_ce", volume_uuid);
res &= destroy_volume_keys("/data/misc_de", volume_uuid);
return res;
}